Pseudo-passive universal communicator system

Claim 2

In apparatus for two-way communication between a transmitter/receiver unit, called a controller, and at least one second transmitter/receiver unit, called a communicator, said controller comprising: (a) first means for generating a carrier signal; (b) second means for modulating said carrier signal with a first informational signal to produce a first modulated carrier signal; (c) third means for transmitting said first modulated carrier signal as a first electromagnetic wave signal to said communicator; (d) fourth means for receiving a second electromagnetic wave signal transmitted by said communicator to reproduce a second modulated carrier signal; and (e) fifth means for demodulating said second modulated carrier signal to reproduce a second informational signal; each of said communicators comprising: (a) sixth means for receiving said first electromagnetic wave signal transmitted by said controller to reproduce said first modulated carrier signal; (b) seventh means for demodulating said first modulated carrier signal to reproduce said first informational signal; (c) eighth means for backscatter modulating said first modulated carrier signal with a second informational signal to produce a second modulated carrier signal; and (d) ninth means for transmitting said second modulated carrier signal as said second electromagnetic wave signal; the improvement wherein said first means comprises means for pseudo-randomly varying the frequency or phase of said carrier signal and said fifth means includes means for mixing said carrier signal with said second modulated carrier signal, thereby to provide security against jamming, eavesdropping, and/or range gating on said first or second electromagnetic wave signal.

Claim 3

The apparatus defined in claim 1, wherein said first means comprises a voltage controlled oscillator (VCO) and means for pseudo-randomly varying the voltage applied to said VCO.

Claim 4

The apparatus defined in claim 1, wherein said first means comprises a frequency synthesizer for producing a signal of substantially constant frequency, and a signal mixer, coupled to the output of said frequency synthesizer, for mixing a pseudo-randomly varying signal with said constant frequency signal, thereby to vary the phase of said frequency signal.

Claim 5

In apparatus for two-way communication between a transmitter/receiver unit, called a controller, and at least one second transmitter/receiver unit, called a communicator, said controller comprising: (a) first means for generating a carrier signal; (b) second means for modulating said carrier signal with a first informational signal to produce a first modulated carrier signal; (c) third means for transmitting said first modulated carrier signal as a first electromagnetic wave signal to said communicator; (d) fourth means for receiving a second electromagnetic wave signal transmitted by said communicator to reproduce a second modulated carrier signal; and (e) fifth means for demodulating said second modulated carrier signal to reproduce a second informational signal; each of said communicators comprising: (a) sixth means for receiving said first electromagnetic wave signal transmitted by said controller to reproduce said first modulated carrier signal; (b) seventh means for demodulating said first modulated carrier signal to reproduce said first informational signal; (c) eighth means for backscatter modulating said first modulated carrier signal with a second informational signal to produce a second modulated carrier signal; and (d) ninth means for transmitting said second modulated carrier signal as said second electromagnetic wave signal; the improvement wherein said third means and said ninth means include means for orthogonally polarizing said first and second electromagnetic wave signals with respect to each other, thereby to minimize cross talk and the sensitivity of the received signals to the relative orientation of said first and second antennas.

Claim 6

In apparatus for two-way communication between a transmitter/receiver unit, called a controller, and at least one second transmitter/receiver unit, called a communicator, said controller comprising: (a) first means for generating a carrier signal; (b) second means for modulating said carrier signal with a first informational signal to produce a first modulated carrier signal; (c) third means for transmitting said first modulated carrier signal as a first electromagnetic wave signal to said communicator; (d) fourth means for receiving a second electromagnetic wave signal transmitted by said communicator to reproduce a second modulated carrier signal; and (e) fifth means for demodulating said second modulated carrier signal to reproduce a second informational signal; each of said communicators comprising: (a) sixth means for receiving said first electromagnetic wave signal transmitted by said controller to reproduce said first modulated carrier signal; (b) seventh means for demodulating said first modulated carrier signal to reproduce said first informational signal; (c) eighth means for backscatter modulating said first modulated carrier signal with a second informational signal to produce a second modulated carrier signal; and (d) ninth means for transmitting said second modulated carrier signal as said second electromagnetic wave signal; the improvement wherein said third means and said ninth means include means for orthogonally polarizing said first and second electromagnetic wave signals with respect to each other, thereby to minimize cross talk and the sensitivity of the received signals to the relative orientation of said first and second antennas.

Claim 7

The apparatus defined in claim 4, wherein said first and second electromagnetic signals are linearly cross polarized.

Claim 8

The apparatus defined in claim 4, wherein said first and second electromagnetic signals are circularly cross polarized.

Claim 9

The apparatus defined in claim 4, wherein said third means and said fourth means include a common first antenna and said sixth means and said ninth means include a common second antenna, said first and said second antennas being configured to transmit and receive orthogonally polarized first and second electromagnetic wave signals, respectively.

Claim 10

In apparatus for two-way communication between a transmitter/receiver unit, called a controller, and at least one second transmitter/receiver unit, called a communicator, said controller comprising: (a) first means for generating a carrier signal; (b) second means for modulating said carrier signal with a first informational signal to produce a first modulated carrier signal; (c) third means for transmitting said first modulated carrier signal as a first electromagnetic wave signal to said communicator; (d) fourth means for receiving a second electromagnetic wave signal transmitted by said communicator to reproduce a second modulated carrier signal; and (e) fifth means for demodulating said second modulated carrier signal to reproduce a second informational signal; each of said communicators comprising: (a) sixth means for receiving said first electromagnetic wave signal transmitted by said controller to reproduce said first modulated carrier signal; (b) seventh means for demodulating said first modulated carrier signal to reproduce said first informational signal; (c) eighth means for backscatter modulating said first modulated carrier signal with a second informational signal to produce a second modulated carrier signal; and (d) ninth means for transmitting said second modulated carrier signal as said second electromagnetic wave signal; the improvement wherein said sixth means and said ninth means include a common antenna, a common quadrature polarization changeover switch, and first and second feed line means connecting said changeover switch with orthogonal first and second feed points, respectively, on said antenna; said changeover switch including means for alternating connections between said first and second feed line means, respectively, on one side, and the output of said sixth means and input of said ninth means, respectively, on the other side, thereby to alternate connection of said antenna between said sixth and said ninth means.

Claim 11

In apparatus for two-way communication between a transmitter/receiver unit, called a controller, and at least one second transmitter/receiver unit, called a communicator, said controller comprising: (a) first means for generating a carrier signal; (b) second means for modulating said carrier signal with a first informational signal to produce a first modulated carrier signal; (c) third means for transmitting said first modulated carrier signal as a first electromagnetic wave signal to said communicator; (d) fourth means for receiving a second electromagnetic wave signal transmitted by said communicator to reproduce a second modulated carrier signal; and (e) fifth means for demodulating said second modulated carrier signal to reproduce a second informational signal; each of said communicators comprising: (a) sixth means for receiving said first electromagnetic wave signal transmitted by said controller to reproduce said first modulated carrier signal; (b) seventh means for demodulating said first modulated carrier signal to reproduce said first informational signal; (c) eighth means for backscatter modulating said first modulated carrier signal with a second informational signal to produce a second modulated carrier signal; and (d) ninth means for transmitting said second modulated carrier signal as said second electromagnetic wave signal; the improvement wherein said sixth means and said ninth means include a common antenna, a common quadrature polarization changeover switch, and first and second feed line means connecting said changeover switch with orthogonal first and second feed points, respectively, on said antenna; said changeover switch including means for alternating connections between said first and second feed line means, respectively, on one side, and the output of said sixth means and input of said ninth means, respectively, on the other side, thereby to alternate connection of said antenna between said sixth and said ninth means.

Claim 12

The apparatus defined in claim 8, wherein said antenna is a patch antenna and said orthogonal first and second feed points are 90° apart around the edge of the antenna with respect to its center.

Claim 13

The apparatus defined in claim 8, wherein said changeover switch comprises four GaAs transistors connected in series with the source of each transistor connected to the drain of another transistor to form a bridge circuit with four node points at the source and drain connections.

Claim 14

The apparatus defined in claim 10, wherein two node points on opposite sides of said bridge circuit are each connected, respectively, to two opposite feed points of said antenna through a capacitor and the two remaining node points on opposite sides of said bridge circuit are each connected, respectively, to the remaining two opposite feed points of said antenna through an inductor.

Claim 15

The apparatus defined in claim 10, wherein said eighth means includes means for applying control signals to the gates of said transistors.

Claim 16

The apparatus defined in claim 12, wherein a common control signal is applied to the gates of two opposite transistors in said bridge circuit and the complement of said common control signal is applied to the gates of the remaining two transistors in said bridge circuit.

Claim 17

In apparatus for two-way communication between a transmitter/receiver unit, called a controller, and at least one second transmitter/receiver unit, called a communicator, said controller comprising: (a) first means for generating a carrier signal; (b) second means for modulating said carrier signal with a first informational signal to produce a first modulated carrier signal; (c) third means for transmitting said first modulated carrier signal as a first electromagnetic wave signal to said communicator; (d) fourth means for receiving a second electromagnetic wave signal transmitted by said communicator to reproduce a second modulated carrier signal; and (e) fifth means for demodulating said second modulated carrier signal to reproduce a second informational signal; each of said communicators comprising: (a) sixth means for receiving said first electromagnetic wave signal transmitted by said controller to reproduce said first modulated carrier signal; (b) seventh means for demodulating said first modulated carrier signal to reproduce said first informational signal; (c) eighth means for backscatter modulating said first modulated carrier signal with a second informational signal to produce a second modulated carrier signal; and (d) ninth means for transmitting said second modulated carrier signal as said second electromagnetic wave signal; the improvement wherein said seventh means comprises a delay line having first and second terminals at opposite ends and connected to receive said first modulated carrier signal at said first terminal and said second modulated carrier signal at said opposite terminal; signal summing means having two inputs and an output; a first diode connecting in the forward direction said first terminal with one of said inputs and a second diode connecting in the forward direction said second terminal with said other input; said output of said summing means providing said first informational signal, independent of the standing wave ratio.

Claim 18

In apparatus for two-way communication between a transmitter/receiver unit, called a controller, and at least one second transmitter/receiver unit, called a communicator, said controller comprising: (a) first means for generating a carrier signal; (b) second means for modulating said carrier signal with a first informational signal to produce a first modulated carrier signal; (c) third means for transmitting said first modulated carrier signal as a first electromagnetic wave signal to said communicator; (d) fourth means for receiving a second electromagnetic wave signal transmitted by said communicator to reproduce a second modulated carrier signal; and (e) fifth means for demodulating said second modulated carrier signal to reproduce a second informational signal; each of said communicators comprising: (a) sixth means for receiving said first electromagnetic wave signal transmitted by said controller to reproduce said first modulated carrier signal; (b) seventh means for demodulating said first modulated carrier signal to reproduce said first informational signal; (c) eighth means for backscatter modulating said first modulated carrier signal with a second informational signal to produce a second modulated carrier signal; and (d) ninth means for transmitting said second modulated carrier signal as said second electromagnetic wave signal; the improvement wherein said seventh means comprises a delay line having first and second terminals at opposite ends and connected to receive said first modulated carrier signal at said first terminal and said second modulated carrier signal at said opposite terminal; signal summing means having two inputs and an output; a first diode connecting in the forward direction said first terminal with one of said inputs and a second diode connecting in the forward direction said second terminal with said other input; said output of said summing means providing said first informational signal, independent of the standing wave ratio.

Claim 19

The apparatus defined in claim 15, wherein said delay line delays the signal passing therethrough by 90° of the phase of said carrier signal.

Claim 20

The apparatus defined on claim 16, wherein said first informational signal forms a serial bit stream, and wherein said delay line delays a signal by one bit period of said first informational signal.

Claim 21

In apparatus for two-way communication between a transmitter/receiver unit, called a controller, and at least one second transmitter/receiver unit, called a communicator, said controller comprising: (a) first means for generating a carrier signal; (b) second means for modulating said carrier signal with a first informational signal to produce a first modulated carrier signal; (c) third means for transmitting said first modulated carrier signal as a first electromagnetic wave signal to said communicator; (d) fourth means for receiving a second electromagnetic wave signal transmitted by said communicator to reproduce a second modulated carrier signal; and (e) fifth means for demodulating said second modulated carrier signal to reproduce a second informational signal; each of said communicators comprising: (a) sixth means for receiving said first electromagnetic wave signal transmitted by said controller to reproduce said first modulated carrier signal; (b) seventh means for demodulating said first modulated carrier signal to reproduce said first informational signal; (c) eighth means for backscatter modulating said first modulated carrier signal with a second informational signal to produce a second modulated carrier signal; and (d) ninth means for transmitting said second modulated carrier signal as said second electromagnetic wave signal; the improvement comprising tracking cancellation circuit means, coupled between said third means and said fourth means, for producing a cancellation signal in dependence upon said first modulated carrier signal, said cancellation signal being injected into the receiving path of said fourth means to reduce echo and cross talk in said second modulated carrier signal.

Claim 22

In apparatus for two-way communication between a transmitter/receiver unit, called a controller, and at least one second transmitter/receiver unit, called a communicator, said controller comprising: (a) first means for generating a carrier signal; (b) second means for modulating said carrier signal with a first informational signal to produce a first modulated carrier signal; (c) third means for transmitting said first modulated carrier signal as a first electromagnetic wave signal to said communicator; (d) fourth means for receiving a second electromagnetic wave signal transmitted by said communicator to reproduce a second modulated carrier signal; and (e) fifth means for demodulating said second modulated carrier signal to reproduce a second informational signal; each of said communicators comprising: (a) sixth means for receiving said first electromagnetic wave signal transmitted by said controller to reproduce said first modulated carrier signal; (b) seventh means for demodulating said first modulated carrier signal to reproduce said first informational signal; (c) eighth means for backscatter modulating said first modulated carrier signal with a second informational signal to produce a second modulated carrier signal; and (d) ninth means for transmitting said second modulated carrier signal as said second electromagnetic wave signal; the improvement comprising tracking cancellation circuit means, coupled between said third means and said fourth means, for producing a cancellation signal in dependence upon said first modulated carrier signal, said cancellation signal being injected into the receiving path of said fourth means to reduce echo and cross talk in said second modulated carrier signal.

Claim 23

The apparatus defined in claim 17, wherein said cancellation circuit means includes means for adjusting the amplitude of said cancellation signal.

Claim 24

The apparatus defined in claim 17, wherein said cancellation circuit means includes means for adjusting the phase of said cancellation signal.

Claim 25

In apparatus for two-way communication between a transmitter/receiver unit, called a controller, and at least one second transmitter/receiver unit, called a communicator, said controller comprising: (a) first means for generating a carrier signal; (b) second means for modulating said carrier signal with a first informational signal to produce a first modulated carrier signal; (c) third means for transmitting said first modulated carrier signal as a first electromagnetic wave signal to said communicator; (d) fourth means for receiving a second electromagnetic wave signal transmitted by said communicator to reproduce a second modulated carrier signal; and (e) fifth means for demodulating said second modulated carrier signal to reproduce a second informational signal; each of said communicators comprising: (a) sixth means for receiving said first electromagnetic wave signal transmitted by said controller to reproduce said first modulated carrier signal; (b) seventh means for demodulating said first modulated carrier signal to reproduce said first informational signal; (c) eighth means for backscatter modulating said first modulated carrier signal with a second informational signal to produce a second modulated carrier signal; and (d) ninth means for transmitting said second modulated carrier signal as said second electromagnetic wave signal; the improvement wherein said fifth means comprises a quadrature detector, coupled to said first means and said fourth means, for producing quadrature in-phase (I) and quadrature phase (Q) outputs and a quadrature summing amplifier, coupled to said quadrature detector, for summing said in-phase and quadrature phase outputs.

Claim 26

In apparatus for two-way communication between a transmitter/receiver unit, called a controller, and at least one second transmitter/receiver unit, called a communicator, said controller comprising: (a) first means for generating a carrier signal; (b) second means for modulating said carrier signal with a first informational signal to produce a first modulated carrier signal; (c) third means for transmitting said first modulated carrier signal as a first electromagnetic wave signal to said communicator; (d) fourth means for receiving a second electromagnetic wave signal transmitted by said communicator to reproduce a second modulated carrier signal; and (e) fifth means for demodulating said second modulated carrier signal to reproduce a second informational signal; each of said communicators comprising: (a) sixth means for receiving said first electromagnetic wave signal transmitted by said controller to reproduce said first modulated carrier signal; (b) seventh means for demodulating said first modulated carrier signal to reproduce said first informational signal; (c) eighth means for backscatter modulating said first modulated carrier signal with a second informational signal to produce a second modulated carrier signal; and (d) ninth means for transmitting said second modulated carrier signal as said second electromagnetic wave signal; the improvement wherein said fifth means comprises a quadrature detector, coupled to said first means and said fourth means, for producing quadrature in-phase (I) and quadrature phase (Q) outputs and a quadrature summing amplifier, coupled to said quadrature detector, for summing said in-phase and quadrature phase outputs.

Claim 27

The apparatus defined in claim 20, wherein said eighth means provides frequency shift key modulation, and wherein said fifth means further includes a frequency shift key demodulator comprising: (1) a first channel coupled to receive the output of said quadrature summing amplifier comprising a first band pass filter and a first log detector connected in series; (2) a second channel coupled to receive the output of said quadrature summing amplifier and comprising a second band pass filter and a second log detector connected in series; and (3) a difference amplifier connected to the outputs of said first and second channels for producing an output signal representing the difference between the output signals received from said first and second channels.

Claim 28

The apparatus defined in claim 21, wherein said frequency shift key demodulator further comprises a summing amplifier connected to the outputs of the first and second channels for producing an output signal representing the sum of the output signals received from said first and second channels.

Claim 29

In apparatus for two-way communication between a transmitter/receiver unit, called a controller, and at least one second transmitter/receiver unit, called a communicator, said controller comprising: (a) first means for generating a carrier signal; (b) second means for modulating said carrier signal with a first informational signal to produce a first modulated carrier signal; (c) third means for transmitting said first modulated carrier signal as a first electromagnetic wave signal to said communicator; (d) fourth means for receiving a second electromagnetic wave signal transmitted by said communicator to reproduce a second modulated carrier signal; and (e) fifth means for demodulating said second modulated carrier signal to reproduce a second informational signal; each of said communicators comprising: (a) sixth means for receiving said first electromagnetic wave signal transmitted by said controller to reproduce said first modulated carrier signal; (b) seventh means for demodulating said first modulated carrier signal to reproduce said first informational signal; (c) eighth means for backscatter modulating said first modulated carrier signal with a second informational signal to produce a second modulated carrier signal; and (d) ninth means for transmitting said second modulated carrier signal as said second electromagnetic wave signal; the improvement wherein said second means includes means for amplitude modulating said carrier signal with three zone bit coding, a first zone bit being modulated at the 100% level; a second zone bit being modulated between the 50 and 100% levels in dependence upon said first informational signal; and a third zone bit being modulated at the 50% level.

Claim 30

In apparatus for two-way communication between a transmitter/receiver unit, called a controller, and at least one second transmitter/receiver unit, called a communicator, said controller comprising: (a) first means for generating a carrier signal; (b) second means for modulating said carrier signal with a first informational signal to produce a first modulated carrier signal; (c) third means for transmitting said first modulated carrier signal as a first electromagnetic wave signal to said communicator; (d) fourth means for receiving a second electromagnetic wave signal transmitted by said communicator to reproduce a second modulated carrier signal; and (e) fifth means for demodulating said second modulated carrier signal to reproduce a second informational signal; each of said communicators comprising: (a) sixth means for receiving said first electromagnetic wave signal transmitted by said controller to reproduce said first modulated carrier signal; (b) seventh means for demodulating said first modulated carrier signal to reproduce said first informational signal; (c) eighth means for backscatter modulating said first modulated carrier signal with a second informational signal to produce a second modulated carrier signal; and (d) ninth means for transmitting said second modulated carrier signal as said second electromagnetic wave signal; the improvement wherein said second means includes means for amplitude modulating said carrier signal with three zone bit coding, a first zone bit being modulated at the 100% level; a second zone bit being modulated between the 50 and 100% levels in dependence upon said first informational signal; and a third zone bit being modulated at the 50% level.

Claim 31

The apparatus defined in claim 23, wherein said seventh means includes means for determining when said third zone bit is at a zero level, and said eighth means includes means for retransmitting the last bit sent when a received third bit is at a zero level.

Claim 32

The apparatus defined in claim 23, wherein said first zone bit is modulated at the 50% level at the beginning of each digital frame.

Claim 33

In apparatus for two-way communication between a transmitter/receiver unit, called a controller, and at least one second transmitter/receiver unit, called a communicator, said controller comprising: (a) first means for generating a carrier signal; (b) second means for modulating said carrier signal with a first informational signal to produce a first modulated carrier signal; (c) third means for transmitting said first modulated carrier signal as a first electromagnetic wave signal to said communicator; (d) fourth means for receiving a second electromagnetic wave signal transmitted by said communicator to reproduce a second modulated carrier signal; and (e) fifth means for demodulating said second modulated carrier signal to reproduce a second informational signal; each of said communicators comprising: (a) sixth means for receiving said first electromagnetic wave signal transmitted by said controller to reproduce said first modulated carrier signal; (b) seventh means for demodulating said first modulated carrier signal to reproduce said first informational signal; (c) eighth means for backscatter modulating said first modulated carrier signal with a second informational signal to produce a second modulated carrier signal; and (d) ninth means for transmitting said second modulated carrier signal as said second electromagnetic wave signal; the improvement wherein said eighth means includes image reject mixer means and means for selecting one of the upper and lower sidebands for single sideband modulation.

Claim 34

In apparatus for two-way communication between a transmitter/receiver unit, called a controller, and at least one second transmitter/receiver unit, called a communicator, said controller comprising: (a) first means for generating a carrier signal; (b) second means for modulating said carrier signal with a first informational signal to produce a first modulated carrier signal; (c) third means for transmitting said first modulated carrier signal as a first electromagnetic wave signal to said communicator; (d) fourth means for receiving a second electromagnetic wave signal transmitted by said communicator to reproduce a second modulated carrier signal; and (e) fifth means for demodulating said second modulated carrier signal to reproduce a second informational signal; each of said communicators comprising: (a) sixth means for receiving said first electromagnetic wave signal transmitted by said controller to reproduce said first modulated carrier signal; (b) seventh means for demodulating said first modulated carrier signal to reproduce said first informational signal; (c) eighth means for backscatter modulating said first modulated carrier signal with a second informational signal to produce a second modulated carrier signal; and (d) ninth means for transmitting said second modulated carrier signal as said second electromagnetic wave signal; the improvement wherein said eighth means includes image reject mixer means and means for selecting one of the upper and lower sidebands for single sideband modulation.

Claim 35

In apparatus for two-way communication between a transmitter/receiver unit, called a controller, and at least one second transmitter/receiver unit, called a communicator, said controller comprising: (a) first means for generating a carrier signal; (b) second means for modulating said carrier signal with a first informational signal to produce a first modulated carrier signal; (c) third means for transmitting said first modulated carrier signal as a first electromagnetic wave signal to said communicator; (d) fourth means for receiving a second electromagnetic wave signal transmitted by said communicator to reproduce a second modulated carrier signal; and (e) fifth means for demodulating said second modulated carrier signal to reproduce a second informational signal; each of said communicators comprising: (a) sixth means for receiving said first electromagnetic wave signal transmitted by said controller to reproduce said first modulated carrier signal; (b) seventh means for demodulating said first modulated carrier signal to reproduce said first informational signal; (c) eighth means for backscatter modulating said first modulated carrier signal with a second informational signal to produce a second modulated carrier signal; and (d) ninth means for transmitting said second modulated carrier signal as said second electromagnetic wave signal; the improvement wherein said fifth means includes image reject mixer means for mixing both said carrier signal and a 90° delayed version of said carrier signal with said second modulated carrier signal; means for separating the upper and lower sidebands; and means for demodulating the selected sideband.

Claim 36

In apparatus for two-way communication between a transmitter/receiver unit, called a controller, and at least one second transmitter/receiver unit, called a communicator, said controller comprising: (a) first means for generating a carrier signal; (b) second means for modulating said carrier signal with a first informational signal to produce a first modulated carrier signal; (c) third means for transmitting said first modulated carrier signal as a first electromagnetic wave signal to said communicator; (d) fourth means for receiving a second electromagnetic wave signal transmitted by said communicator to reproduce a second modulated carrier signal; and (e) fifth means for demodulating said second modulated carrier signal to reproduce a second informational signal; each of said communicators comprising: (a) sixth means for receiving said first electromagnetic wave signal transmitted by said controller to reproduce said first modulated carrier signal; (b) seventh means for demodulating said first modulated carrier signal to reproduce said first informational signal; (c) eighth means for backscatter modulating said first modulated carrier signal with a second informational signal to produce a second modulated carrier signal; and (d) ninth means for transmitting said second modulated carrier signal as said second electromagnetic wave signal; the improvement wherein said fifth means includes image reject mixer means for mixing both said carrier signal and a 90° delayed version of said carrier signal with said second modulated carrier signal; means for separating the upper and lower sidebands; and means for demodulating the selected sideband.

Claim 37

In apparatus for two way communication between a transmittor/receiver unit, called a controller, and at least one second transmittor/receiver unit, called a communicator, the improvement wherein said communicator comprises a telephone handset having four separate, substantially planar sections, said sections being serially connected by means of hinges which permit said sections to be folded together in a collapsed, carrying position or opened outwardly into an operative, communicating position, said sections consisting of: (1) a first section adapted to support a telephone microphone; (2) a second section adapted to support a key pad for telephone dialing; (3) a third section adapted to support a telephone loudspeaker; and (4) a fourth section adapted to support a patch antenna for communication by electromagnetic waves with a remote controller.

Claim 38

In apparatus for two way communication between a transmittor/receiver unit, called a controller, and at least one second transmittor/receiver unit, called a communicator, the improvement wherein said communicator comprises a telephone handset having four separate, substantially planar sections, said sections being serially connected by means of hinges which permit said sections to be folded together in a collapsed, carrying position or opened outwardly into an operative, communicating position, said sections consisting of: (1) a first section adapted to support a telephone microphone; (2) a second section adapted to support a key pad for telephone dialing; (3) a third section adapted to support a telephone loudspeaker; and (4) a fourth section adapted to support a patch antenna for communication by electromagnetic waves with a remote controller.

Claim 39

The apparatus defined in claim 26, wherein said fourth section, when folded outwardly, is disposed substantially horizontally when the remaining sections of said handset are outwardly folded and said handset is held by a user in a conventional operating position.

Claim 40

The apparatus defined in claim 28, wherein said fourth section, when folded outwardly, is disposed substantially horizontally when the remaining sections of said handset are folded together in a collapsed position and said handset is disposed in a substantially vertical position.