Reactance buffered loop antenna and method for making the same

Claim 2

A reactance buffer, for maintaining a substantially constant resonant frequency for a loop antenna having a plurality of selectable loop circumferences, the loop antenna formed from first and second conductor antenna segments, each antenna segment having first and second ends, the first ends of each antenna segment being coupled to a receiver input, the second ends of each antenna segment being selectably coupled for providing adjustment of the loop circumference, said buffer comprising: a reactance buffer input coupled to the second end of the first antenna segment; a plurality of taps, linearly disposed along a longitudinal axis of the reactance buffer, the distance between the outermost of said plurality of taps providing a predetermined length corresponding to the length of adjustment of the loop circumference, said taps providing selectable coupling positions for coupling to the second end of the second antenna segment; and a plurality of reactance elements, arranged non-serially between said reactance buffer input and each of said plurality of taps, wherein one or more of said reactance elements are coupled between said input and a corresponding one of said taps to provide a substantially constant reactance when measured between said reactance buffer input and each of said plurality of taps, whereby the resonant frequency of the loop antenna remains substantially constant when the loop circumference is adjusted.

Claim 3

The reactance buffer according to claim 1, wherein said reactance elements are inductive elements.

Claim 4

The reactance buffer according to claim 2, wherein the magnitude of the inductance measured between the buffer input and each tap is substantially constant.

Claim 5

The reactance buffer according to claim 2, wherein each of said inductive elements is formed from a conductor.

Claim 6

The reactance buffer according to claim 4, wherein said conductors are formed from sheet metal.

Claim 7

The reactance buffer according to claim 5, wherein said sheet metal is selected from a group of sheet metals consisting of copper, beryllium copper, and nickel silver.

Claim 8

The reactance buffer according to claim 1, wherein said reactance elements comprise a plurality of paired inductive and capacitive elements defining inductor/capacitor pairs.

Claim 9

The reactance buffer according to claim 7, wherein said inductive elements are coupled in series with said buffer input.

Claim 10

The reactance buffer according to claim 7, wherein each of said inductive elements if formed from a conductor.

Claim 11

The reactance buffer according to claim 9, wherein said conductors are formed from sheet metal.

Claim 12

The reactance buffer according to claim 10, wherein said sheet metal is selected from a group of sheet metals consisting of copper, beryllium copper, and nickel silver.

Claim 13

The reactance buffer according to claim 7, wherein said capacitive elements are fixed value capacitors.

Claim 14

The reactance buffer according to claim 12, wherein each inductor of each inductor/capacitor pair has an input and an output terminal, each of said capacitors of each inductor/capacitor pair has an input and an output terminal, each capacitor input terminal being coupled to a respective inductor output terminal, and each capacitor output terminal being coupled to a respective one of said plurality of taps.

Claim 15

The reactance buffer according to claim 13, wherein the magnitude of 2πfL cum +1/(2πfC tap ) measured from said buffer input to each of said plurality of taps is substantially constant, f being the frequency of operation, L cum being the cumulative inductance associated with each of said plurality of taps, and C tap being the tap capacitance of each of said inductor/capacitor pairs coupled to each of said plurality of taps.

Claim 16

The reactance buffer according to claim 4, wherein the inductance of each inductive element is controlled by the conductor geometry.

Claim 17

The reactance buffer according to claim 9, wherein the inductance of each inductive element is controlled by the conductor geometry.

Claim 18

A buffered loop antenna, having a plurality of selectable loop circumferences, the loop antenna being coupled to a receiver having signal and ground inputs coupled to an antenna resonating capacitor for resonating the loop antenna to a predetermined frequency, said loop antenna comprising: a first conductor, having a first end coupled to the receiver signal input and a second end, said first conductor forming a first portion of the loop antenna; a second conductor, having a first end coupled to the receiver ground and a second end, said second conductor forming a second portion of the loop antenna; reactance buffer means, comprising a reactance buffer input coupled to said second end of said first conductor, a plurality of taps linearly disposed along a longitudinal axis of said reactance buffer the distance between the outermost of said plurality of taps providing a predetermined length corresponding to the loop circumference adjustment, and a plurality of reactance elements, arranged non-serially between said reactance buffer input and each of said plurality of taps, wherein one or more of said reactance elements are coupled between said input and a corresponding one of said taps to provide a substantially constant reactance when measured between said reactance buffer input and each of said plurality of taps; and coupling means, coupled to said second end of said second conductor, for coupling said second conductor to any of said plurality of taps, whereby the resonant frequency of the loop antenna remains substantially constant when any of said plurality of taps is selected to adjust the loop circumference.

Claim 19

A buffered loop antenna, having a plurality of selectable loop circumferences, the loop antenna being coupled to a receiver having signal and ground inputs coupled to an antenna resonating capacitor for resonating the loop antenna to a predetermined frequency, said loop antenna comprising: a first conductor, having a first end coupled to the receiver signal input and a second end, said first conductor forming a first portion of the loop antenna; a second conductor, having a first end coupled to the receiver ground and a second end, said second conductor forming a second portion of the loop antenna; reactance buffer means, comprising a reactance buffer input coupled to said second end of said first conductor, a plurality of taps linearly disposed along a longitudinal axis of said reactance buffer the distance between the outermost of said plurality of taps providing a predetermined length corresponding to the loop circumference adjustment, and a plurality of reactance elements, arranged non-serially between said reactance buffer input and each of said plurality of taps, wherein one or more of said reactance elements are coupled between said input and a corresponding one of said taps to provide a substantially constant reactance when measured between said reactance buffer input and each of said plurality of taps; and coupling means, coupled to said second end of said second conductor, for coupling said second conductor to any of said plurality of taps, whereby the resonant frequency of the loop antenna remains substantially constant when any of said plurality of taps is selected to adjust the loop circumference.

Claim 20

The buffered loop antenna according to claim 17 wherein said first and second conductors are sheet metal.

Claim 21

The buffered loop antenna according to claim 18 wherein said sheet metal is selected from a group consisting of copper, beryllium copper, and nickel silver.

Claim 22

A wristband loop antenna for a wrist worn electronic device, the device including a receiver having signal and ground inputs coupled to an antenna resonating capacitor for resonating the loop antenna to a predetermined frequency, said wristband loop antenna comprising: a first wristband section, including a first conductor, having a first end for coupling to the receiver signal input and a second end, said first conductor forming a first portion of the loop antenna within said first wristband second, and reactance buffer means, comprising a reactance buffer input coupled to said second end of said first conductor, a plurality of taps linearly disposed along a longitudinal axis of said reactance buffer the distance between the outermost of said plurality of taps providing a predetermined length corresponding to the loop antenna diameter adjustment, and a plurality of reactance elements, arranged non-serially between said reactance buffer input and each of said plurality of taps, wherein one or more of said reactance elements are coupled between said input and a corresponding one of said taps to provide a substantially constant reactance when measured between said reactance buffer input and each of said plurality of taps; and a second wristband section including a second conductor, having a first end coupled to the receiver ground and a second end, said second conductor forming a second portion of the loop antenna within said second wristband section, and coupling means, coupled to said second end of said second conductor, for coupling said second conductor to any of said plurality of taps, whereby when the wristband length is adjusted by selecting any of said plurality of taps, the resonant frequency of said loop antenna remains substantially unchanged.

Claim 23

A wristband loop antenna for a wrist worn electronic device, the device including a receiver having signal and ground inputs coupled to an antenna resonating capacitor for resonating the loop antenna to a predetermined frequency, said wristband loop antenna comprising: a first wristband section, including a first conductor, having a first end for coupling to the receiver signal input and a second end, said first conductor forming a first portion of the loop antenna within said first wristband second, and reactance buffer means, comprising a reactance buffer input coupled to said second end of said first conductor, a plurality of taps linearly disposed along a longitudinal axis of said reactance buffer the distance between the outermost of said plurality of taps providing a predetermined length corresponding to the loop antenna diameter adjustment, and a plurality of reactance elements, arranged non-serially between said reactance buffer input and each of said plurality of taps, wherein one or more of said reactance elements are coupled between said input and a corresponding one of said taps to provide a substantially constant reactance when measured between said reactance buffer input and each of said plurality of taps; and a second wristband section including a second conductor, having a first end coupled to the receiver ground and a second end, said second conductor forming a second portion of the loop antenna within said second wristband section, and coupling means, coupled to said second end of said second conductor, for coupling said second conductor to any of said plurality of taps, whereby when the wristband length is adjusted by selecting any of said plurality of taps, the resonant frequency of said loop antenna remains substantially unchanged.

Claim 24

The wristband antenna according to claim 20 wherein said first wristband section further includes compliant top and bottom members for enclosing said first conductor and said reactance buffer means, and said second wristband section further includes compliant top and bottom members for enclosing said second conductor.

Claim 25

The wristband antenna according to claim 21 wherein said top and bottom members are molded from a urethane rubber.

Claim 26

The wristband antenna according to claim 21 wherein said top and bottom members are die cut from leather.

Claim 27

The wristband antenna according to claim 20 wherein said first and second wristband sections further include attachment means for attaching said wristband sections to the electronic device.

Claim 28

The wristband antenna according to claim 20 wherein said first and second conductors are sheet metal.

Claim 29

The wristband antenna according to claim 25 wherein said sheet metal is selected from a group consisting of copper, beryllium copper, and nickel silver.

Claim 30

A wrist worn receiving device, comprising: a receiver located within a housing; and a wrist band, including first and second wrist band sections coupled to said housing, for securing the housing to a users wrist, said first wristband section forming a first portion of a loop antenna, and including a reactance buffer having an input coupled to said receiver, and a plurality of outputs linearly disposed along a longitudinal axis of said first wristband section opposite said housing, said reactance buffer comprising a plurality of reactance elements, arranged non-serially between said reactance buffer input and each of said plurality of outputs, wherein one or more of said reactance elements are coupled between said input and a corresponding one of said outputs for providing a substantially constant reactance measured between said reactance buffer input and each of said reactance buffer outputs, said second wristband section forming a second portion of the loop antenna, and including a coupling means, coupled to said receiver and affixed to said second wristband section opposite said housing, said coupling means providing selective coupling to said plurality of reactance buffer outputs when securing the housing to the users wrist, whereby the length of said wristband is freely adjustable to fit the users wrist by coupling said coupling means to a corresponding one of said plurality of reactance buffer outputs, and whereby the resonant frequency of said loop antenna remains substantially unchanged when said coupling means is coupled to any of said plurality of outputs.

Claim 31

A wrist worn receiving device, comprising: a receiver located within a housing; and a wrist band, including first and second wrist band sections coupled to said housing, for securing the housing to a users wrist, said first wristband section forming a first portion of a loop antenna, and including a reactance buffer having an input coupled to said receiver, and a plurality of outputs linearly disposed along a longitudinal axis of said first wristband section opposite said housing, said reactance buffer comprising a plurality of reactance elements, arranged non-serially between said reactance buffer input and each of said plurality of outputs, wherein one or more of said reactance elements are coupled between said input and a corresponding one of said outputs for providing a substantially constant reactance measured between said reactance buffer input and each of said reactance buffer outputs, said second wristband section forming a second portion of the loop antenna, and including a coupling means, coupled to said receiver and affixed to said second wristband section opposite said housing, said coupling means providing selective coupling to said plurality of reactance buffer outputs when securing the housing to the users wrist, whereby the length of said wristband is freely adjustable to fit the users wrist by coupling said coupling means to a corresponding one of said plurality of reactance buffer outputs, and whereby the resonant frequency of said loop antenna remains substantially unchanged when said coupling means is coupled to any of said plurality of outputs.

Claim 32

The wrist worn receiving device according to claim 27, wherein each of said reactance elements are formed from a conductor.

Claim 33

The wrist worn receiving device according to claim 28, wherein said conductors are formed from sheet metal.

Claim 34

The wrist worn receiving device according to claim 29, wherein said sheet metal is selected from a group of sheet metals consisting of copper, beryllium copper, and nickel silver.

Claim 35

The wrist worn receiving device according to claim 27 wherein said first and second wrist band sections further include attachment means for coupling said first and second wrist band sections to said housing.

Claim 36

The wrist worn receiving device according to claim 27 wherein said first wrist band section further includes a first conductor coupled between said reactance buffer input and said receiver to form the first portion of the loop antenna, and further wherein said second wrist band section further includes a second conductor coupled between said coupling means and said receiver to form the second portion of the loop antenna.

Claim 37

The wrist worn receiving device according to claim 32 wherein said first and second conductors are sheet metal.

Claim 38

The wrist worn receiving device according to claim 33 wherein said sheet metal is selected from a group consisting of copper, beryllium copper, and nickel silver.

Claim 39

The wrist worn receiving device according to claim 27 wherein said first and second wrist band sections are molded from a urethane rubber.

Claim 40

The wrist worn receiving device according to claim 27 wherein said first and second wrist band sections are die cut from leather.

Claim 41

The wrist worn receiving device according to claim 27 wherein said coupling means is a conductive clasp for providing adjustment of the wrist band length and electrical coupling of the first and second antenna portions.