Miniature, low voltage, low current receiver front end

Claim 2

In a receiver for receiving radio frequency signals at a signal input to be converted into intermediate frequency signals and applied to IF signal utilization means, and including a power supply to apply operating potential to the receiver, the combination including: mixer means having first and second inputs and an output coupled to the IF signal utilization means; means coupled to said first input of said mixer means for applying thereto a signal of a predetermined frequency which is different than the frequency of the radio frequency signals to combine therewith and develop the intermediate Frequency signals; RF amplifier means having an input for receiving the radio frequency signals from the signal input of the receiver and an output; and inductance means direct current coupled in series current relation between said output of said RF amplifier means and said second input of said mixer means to form a common current path from the power supply through said mixer means and said RF amplifier means.

Claim 3

The receiver of claim 1 wherein said mixer means includes a current control device having load electrodes and a control electrode, said load electrodes being arranged for receiving current from the power supply of the receiver, said RF amplifier means including a second current control device having a pair of load electrodes and a control electrode, said load electrodes of said second current control device being connected in series with the load electrodes of the current control device of the mixer means so that current from the power supply passes through the load electrodes of said mixer means and through the load electrodes of said RF amplifier means in series.

Claim 4

The receiver of claim 1 including a local oscillator circuit within the receiver for producing said signal of said predetermined frequency, said local oscillator circuit having an output thereof direct current coupled to said first input of said mixer means.

Claim 5

The receiver of claim 3 wherein said inductance means has a tap thereon, and including RF bypass means connecting said tap to a reference potential, and direct current coupling means connected between said tap and said oscillator circuit to control the output amplitude of said oscillator circuit in response to the amplitude of said predetermined frequency applied to said first input of said mixer means.

Claim 6

The receiver of claim 4 wherein said oscillator circuit includes a current control device having a control electrode, and said direct current coupling means between the tap on said inductance means and said oscillator circuit is connected to said control electrode of said current control device, and a bypass capacitor having one end thereof connected to the control electrode of said current control device and the other end thereof connected to the power supply of the receiver.

Claim 7

The receiver of claim 5 wherein said current control device is a transistor having a base-emitter junction thereof connected in parallel with the first and second inputs of said mixer means for direct current and rendered conductive to an extent determined by the radio frequency voltage between said first and second inputs of said mixer means to control the output amplitude of said oscillator circuit.

Claim 8

The receiver of claim 4 wherein the oscillator circuit includes a transistor having an output load electrode, and said mixer means includes a transistor having a base electrode which forms the first input of said mixer means, and means for direct current coupling said load electrode of said oscillator transistor to said base electrode of said mixer transistor.

Claim 9

The receiver of claim 1 wherein said mixer means includes a transistor having base, emitter and collector electrodes, with said collector electrode connected to the power supply of the receiver, and said emitter electrode direct current coupled to said RF amplifier means, and including an oscillator circuit including a transistor having a collector electrode direct current coupled to said base electrode of said transistor of said mixer means, and wherein said RF amplifier means includes a transistor having a collector electrode direct current coupled to said emitter electrode of said transistor of said mixer means, such that common current flows in series through the collector-emitter path of said transistor of said mixer means and the collector-emitter path of said transistor of said RF amplifier means.

Claim 10

The receiver of claim 8 including an oscillator control circuit having a transistor which has a base electrode direct current coupled to said tap on saiD inductance means and a collector electrode direct current coupled to the base electrode of said transistor in said oscillator circuit.

Claim 11

The receiver of claim 1 wherein said mixer means includes a transistor having a base electrode which forms said first input of said mixer means and an emitter electrode which forms said second input of said mixer means, and said inductance means includes an inductor having a tap at an intermediate point thereon, and including a control transistor having a base electrode direct current coupled to said tap on said inductor, said control transistor further having an emitter electrode connected to the power supply such that the DC paths through the base-emitter junctions of said transistor of said mixer means and said control are in parallel.

Claim 12

The receiver of claim 10 wherein said transistor of said mixer means is a high frequency transistor which develops a predetermined voltage across the base-emitter junction thereof when forward biased by a DC voltage, and said control transistor is a low frequency transistor which when forward biased by a DC voltage develops a voltage between the base-emitter junction thereof which is less than the voltage across the base-emitter junction of the transistor of said mixer means.

Claim 13

The receiver of claim 1 including an IF amplifier stage having a transistor with a base electrode direct current coupled to said output of said mixer means, a diode connected in series in the direct current coupling between said mixer means and said base electrode, and feedback means connected from the output of said IF amplifier stage to the input of said RF amplifier means.

Claim 14

The receiver of claim 1 wherein said inductance means is an inductor having a tap at an intermediate point thereon, a capacitor connected in parallel with said inductor to form a tank circuit to match the impedance of said output of said RF amplifier means to said second input of said mixer means, a control transistor having the base-emitter junction thereof connected in parallel with said first and second inputs of said mixer means to control the amplitude of said means coupled to said first input of said mixer means, said base electrode of said control transistor being direct current coupled to said tap on said inductor.

Claim 15

The receiver of claim 13 including a tank circuit formed by an inductance element and a capacitance element connected to said input of said RF amplifier means, said inductance element having a tap at an intermediate point thereon, means connecting the signal input means of said receiver to said tap on said inductance element, and bias voltage means connected to said tank circuit to be direct current coupled therethrough to said input of said RF amplifier means to control the operation of said RF amplifier means.

Claim 16

The receiver of claim 14 including an IF amplifier stage having an input direct current coupled to said output of said mixer means, and wherein said bias voltage means is coupled to said IF amplifier stage and derives a voltage therefrom which varies in accordance with the amplitude of the output signal of said IF amplifier stage which is applied to said tank circuit and to said input of said RF amplifier means.

Claim 17

In a receiver for receiving radio frequency signals at a signal input to be converted into intermediate frequency signals and applied to IF signal utilization means, the combination including: local oscillator means for producing an output signal of a predetermined frequency which is different than the frequency of the radio frequency signals by a predetermined amount to combine therewith and develop the intermediate frequency signals; mixer means having first and second inputs and an output, said output of said mixer means being adapted to be coupled to the IF signal utilization means; coupling means connected between said local oscillator means and said first input of said mixer means for applying the output signal thereto, sAid second input of said mixer means being coupled to the input means of said receiver to receive the radio frequency signal therefrom; and oscillator control means coupled to said local oscillator means to control the amplitude of said output signal thereof, and connected to said mixer means and being rendered conductive in accordance with the amplitude of the signal applied to said first input of said mixer means.

Claim 18

In a receiver for receiving radio frequency signals at a signal input to be converted into intermediate frequency signals and applied to IF signal utilization means, the combination including: local oscillator means for producing an output signal of a predetermined frequency which is different than the frequency of the radio frequency signals by a predetermined amount to combine therewith and develop the intermediate frequency signals; mixer means having first and second inputs and an output, said output of said mixer means being adapted to be coupled to the IF signal utilization means; coupling means connected between said local oscillator means and said first input of said mixer means for applying the output signal thereto, sAid second input of said mixer means being coupled to the input means of said receiver to receive the radio frequency signal therefrom; and oscillator control means coupled to said local oscillator means to control the amplitude of said output signal thereof, and connected to said mixer means and being rendered conductive in accordance with the amplitude of the signal applied to said first input of said mixer means.

Claim 19

The receiver of claim 16 wherein said oscillator control means includes a transistor having a base-emitter junction connected in parallel with said first and second inputs of said mixer means, the conductivity of which is controlled by the voltage between said first and second inputs.

Claim 20

The receiver of claim 16 wherein said mixer means includes a transistor having a base electrode forming said first input of said mixer means and an emitter electrode forming said second input of said mixer means, and said oscillator control means includes a transistor having a base electrode direct current coupled to said emitter electrode of said transistor of said mixer means and an emitter electrode direct current coupled to said base electrode of said transistor of said mixer means, such that DC paths through the base-emitter junctions of said transistor of said mixer means and said transistor of said oscillator control means are in parallel.

Claim 21

The receiver of claim 18 wherein said transistor of said mixer means is a high frequency transistor which develops a predetermined voltage across the base-emitter junction thereof when forward biased by a DC voltage, and said control transistor is a low frequency transistor which when forward biased by a DC voltage develops a voltage across the base-emitter junction thereof less than the voltage across the base-emitter junction of said transistor of said mixer means.

Claim 22

A receiver for receiving radiated radio frequency signals including in combination: RF amplifier means for receiving the radio frequency signals from an input of the receiver and providing amplified radio frequency signals at an output of said RF amplifier means; mixer means having first and second inputs and an output; first means direct current coupling the output of said RF amplifier means in series current relation with said first input of said mixer means; oscillator means for generating an output signal of predetermined frequency at an output of said oscillator means, said oscillator means having a control terminal; second means direct current coupling said output signal from said oscillator means to said second input of said mixer means to cause said mixer means to develop an intermediate frequency signal; an oscillator control circuit having an input and an output; third means direct current coupling said output of said oscillator control circuit to said control terminal of said oscillator means; and fourth means direct current coupling said input of said oscillator control circuit to said first means along the direct current coupling between said RF amplifier means and said mixer means, whereby the interconnection between said RF amplifier means and said mixer means and between said oscillator control circuit and said oscillator means are formed by direct current couplings.

Claim 23

A receiver for receiving radiated radio frequency signals including in combination: RF amplifier means for receiving the radio frequency signals from an input of the receiver and providing amplified radio frequency signals at an output of said RF amplifier means; mixer means having first and second inputs and an output; first means direct current coupling the output of said RF amplifier means in series current relation with said first input of said mixer means; oscillator means for generating an output signal of predetermined frequency at an output of said oscillator means, said oscillator means having a control terminal; second means direct current coupling said output signal from said oscillator means to said second input of said mixer means to cause said mixer means to develop an intermediate frequency signal; an oscillator control circuit having an input and an output; third means direct current coupling said output of said oscillator control circuit to said control terminal of said oscillator means; and fourth means direct current coupling said input of said oscillator control circuit to said first means along the direct current coupling between said RF amplifier means and said mixer means, whereby the interconnection between said RF amplifier means and said mixer means and between said oscillator control circuit and said oscillator means are formed by direct current couplings.

Claim 24

The receiver of claim 20 wherein said first means includes an inductance element having a tap thereon connected in series between said output of said RF amplifier means and said first input of said mixer means, and said fourth means couples said tap on said inductance element to said input of said oscillator control circuit to control the output amplitude of said oscillator circuit in response to the amplitude of said oscillator output signal applied to said second input of said mixer means.

Claim 25

The receiver of claim 21 wherein said oscillator control circuit includes a transistor having a control electrode, and said fourth means is connected to said control electrode, and including a bypass capacitoR having one end thereof connected to said control electrode and the other end thereof adapted to be connected to a reference potential.

Claim 26

The receiver of claim 20 wherein said oscillator control circuit includes a transistor having a base-emitter junction connected in parallel with said first and second inputs of said mixer means, with said transistor being rendered conductive to a degree determined by the voltage between said first and second inputs of said mixer means to control the amplitude of said output signal of said oscillator circuit.

Claim 27

The receiver of claim 20 wherein said mixer means includes a transistor having a collector electrode connected to the power supply for the receiver, an emitter electrode direct current coupled to said RF amplifier means, said oscillator means includes a transistor having a collector electrode direct current coupled to the base electrode of said transistor of said mixer means, and said RF amplifier means includes a transistor having a collector electrode direct current coupled to said emitter electrode of said transistor of said mixer means, such that common current will flow through the collector-emitter path of said transistor of said mixer means and the collector-emitter path of said transistor of said RF amplifier means.

Claim 28

The receiver of claim 20 wherein said mixer means includes a transistor having a base electrode forming said second input of said mixer means and an emitter electrode forming said first input of said mixer means, and said oscillator control circuit includes a control transistor having a base electrode direct current coupled to said emitter electrode of said transistor of said mixer means and an emitter electrode direct current coupled to said base electrode of said transistor of said mixer means, such that the effective DC relationship of the base-emitter junction of said transistor in said mixer means and said transistor of said oscillator control circuit are in parallel.

Claim 29

The receiver of claim 25 wherein said transistor of said mixer means is a high frequency transistor which develops a predetermined voltage across the base-emitter junction thereof when forward biased by a DC voltage, and said transistor of said oscillator control circuit is a low frequency transistor which when forward biased by a DC voltage develops a voltage across the base-emitter junction thereof less than the voltage across the base-emitter junction of said transistor of said mixer means.

Claim 30

In a receiver for receiving RF signal information at a signal input of the receiver to be converted into IF signal information and applied to IF signal utilization means, the combination including: a mixer stage including a first current control device having control, common and output electrodes, said control electrode forming a first input of said mixer stage, and said common electrode forming a second input of said mixer stage; RF translating means connected between the signal input of the receiver and said second input of said first current control device to apply the RF signal information thereto; an oscillator circuit having input and output terminals, circuit means coupling said output terminal of said oscillator circuit to said first input of said first current control device to apply thereto an oscillator frequency signal to be combined with the RF signal information at said second input to produce the IF signal information at said output electrode of said first current control device; an oscillator control circuit including a second current control device having control, common and output electrodes, said output electrode of said second current control device being coupled to said input of said oscillator circuit, and said common electrode and said control electrode of said second current control device being connected in DC parallel relation with said first and second inputs of said mixer stage; and means in circuit with said first and second inputs of said mixeR stage to provide a DC voltage across said first and second inputs thereof which is greater than the DC voltage between said control and common electrodes of said second current control device; said oscillator frequency signal at the output of said oscillator circuit which is injected into said first input of said mixer stage causing a decrease in voltage between said first and second inputs thereof to thereby cause the conduction of said second current control device to decrease and regulate the amplitude of the oscillator frequency signal.

Claim 31

In a receiver for receiving RF signal information at a signal input of the receiver to be converted into IF signal information and applied to IF signal utilization means, the combination including: a mixer stage including a first current control device having control, common and output electrodes, said control electrode forming a first input of said mixer stage, and said common electrode forming a second input of said mixer stage; RF translating means connected between the signal input of the receiver and said second input of said first current control device to apply the RF signal information thereto; an oscillator circuit having input and output terminals, circuit means coupling said output terminal of said oscillator circuit to said first input of said first current control device to apply thereto an oscillator frequency signal to be combined with the RF signal information at said second input to produce the IF signal information at said output electrode of said first current control device; an oscillator control circuit including a second current control device having control, common and output electrodes, said output electrode of said second current control device being coupled to said input of said oscillator circuit, and said common electrode and said control electrode of said second current control device being connected in DC parallel relation with said first and second inputs of said mixer stage; and means in circuit with said first and second inputs of said mixeR stage to provide a DC voltage across said first and second inputs thereof which is greater than the DC voltage between said control and common electrodes of said second current control device; said oscillator frequency signal at the output of said oscillator circuit which is injected into said first input of said mixer stage causing a decrease in voltage between said first and second inputs thereof to thereby cause the conduction of said second current control device to decrease and regulate the amplitude of the oscillator frequency signal.

Claim 32

The receiver of claim 27 wherein said first current control device of said mixing stage is a high frequency transistor having base, emitter and collector electrodes and is responsive to the RF signal information at the emitter electrode thereof, which forms second input of said mixer stage, said first current control device being further responsive to the oscillator frequency signal applied at said base electrode thereof, which forms said first input, to produce the IF signal information at said collector electrode, and said second current control device of said oscillator control circuit is a low frequency transistor connected to said oscillator circuit to control the bias supplied to said oscillator circuit thereby controlling the amplitude of the oscillator frequency signal applied to said base electrode of said high frequency transistor.

Claim 33

The receiver of claim 27 wherein the output of said oscillator circuit is direct current coupled to said control electrode of said first current control device, and said output electrode of said second current control device is direct current coupled to said input terminal of said oscillator circuit.

Claim 34

The receiver of claim 27 wherein the voltage between said first and second inputs of said mixer stage is reduced to a value equal to the voltage between said control and common electrodes of said second current control device upon the application of said oscillator frequency signal to said first input of said mixer stage.

Claim 35

A transistor circuit for amplifying a radio frequency signal and operating from a direct current power supply, including in combination, first and second transistors each having base, emitter and collector electrodes, resonant circuit means including inductor means and capacitor means connected in parallel and resonant at the frequency of the signal, said inductor means including first and second portions having a common junction, and means having low impedance at the frequency of the signal connecting said junction to a reference potential, direct current circuit means connecting said first and second transistors and said resonant circuit means to the power supply to provide a series direct current energizing path through said emitter and collector electrodes of said first transistor, said inductor means and said emitter and collector electrodes of said second transistor, first circuit means applying a radio frequency signal to said base electrode of said first transistor, and second circuit means connecting said base electrode of said second transistor to a reference potential, said second circuit means having a low impedance at the frequency of the signal, said resonant circuit means applying the signal from said collector electrode of said first transistor to said emitter electrode of said second transistor, said portions of said inductor means of said resonant circuit means being selected to match the impedance at said collector electrode of said first transistor to the impedance at said emitter electrode of said second transistor.

Claim 36

A transistor circuit for amplifying a radio frequency signal and operating from a direct current power supply, including in combination, first and second transistors each having base, emitter and collector electrodes, resonant circuit means including inductor means and capacitor means connected in parallel and resonant at the frequency of the signal, said inductor means including first and second portions having a common junction, and means having low impedance at the frequency of the signal connecting said junction to a reference potential, direct current circuit means connecting said first and second transistors and said resonant circuit means to the power supply to provide a series direct current energizing path through said emitter and collector electrodes of said first transistor, said inductor means and said emitter and collector electrodes of said second transistor, first circuit means applying a radio frequency signal to said base electrode of said first transistor, and second circuit means connecting said base electrode of said second transistor to a reference potential, said second circuit means having a low impedance at the frequency of the signal, said resonant circuit means applying the signal from said collector electrode of said first transistor to said emitter electrode of said second transistor, said portions of said inductor means of said resonant circuit means being selected to match the impedance at said collector electrode of said first transistor to the impedance at said emitter electrode of said second transistor.

Claim 37

A transistor circuit in accordance with claim 31 including circuit means connected to said second transistor forming a mixer circuit therewith, and including means applying a local oscillator signal to said base electrode of said second transistor and means deriving an intermediate frequency signal from said collector electrode of said second transistors.

Claim 38

A transIstor circuit in accordance with claim 31 further including local oscillator means for providing a local oscillator signal, control means for said local oscillator means coupled to said inductor means for controlling the amplitude of the local oscillator signal in accordance with the signal in said inductor means, circuit means connecting said local oscillator means to one of said first and second transistors for applying said local oscillator signal thereto, whereby said local oscillator signal is mixed with the radio frequency signal to produce an intermediate frequency signal.

Claim 39

The transistor circuit of claim 31 further including neutralizing capacitor means connected from said emitter electrode of said second transistor to said base electrode of said first transistor.