Patent ID: 6366764
Filing Date: 2002-04-02
Classification: H01Q,H04B

Abstract:
A wireless transmitter/receiver circuit disposed on a PC board assembly, comprising:a transmitting antenna and a receiving antenna, for transmitting and receiving, respectively, a digitally modulated carrier signal, a transmit/receive switching control circuit for selecting said transmitting and receiving antennas, said transmit/receive switching control circuit comprising a first diode and a second diode for antenna selection and isolation, said switching control circuit further comprising a serial combination of a compensating inductance and a DC blocking capacitor connected across said first diode, and a compensating capacitor connected in series with said second diode, wherein said transmit/receive switching control circuit is configured on said PC board assembly so as to form a one quarter wavelength high impedance transmission line between said second diode and ground, wherein the parasitic capacitance of said first diode resonates with said compensating inductance when said first diode is in the off mode, and wherein the parasitic inductance of said second diode resonates with said compensating capacitor when said second diode is in the on mode, a Power Amplifier assembly connected to said transmitting antenna via said transmit/receive switching control circuit, having a power amplifier circuit for amplifying said digitally modulated carrier signal prior to its being transmitted by said transmitting antenna, wherein said power amplifier circuit comprises a gate controlled multi-stage amplifier, having a gate bias circuit for switching said multi-stage amplifier on and off, a Low Noise Amplifier circuit connected to said receiving antenna via said transmit/receive switching control circuit, for amplifying said digitally modulated carrier signal after being received by said receiving antenna, a down converter circuit connected to an output of said Low Noise Amplifier for converting said received digitally modulated carrier signal from RP to IF, a quadrature demodulator/modulator circuit connected to an output of said down converter circuit for demodulating said received digitally modulated IF carrier signal to a digitally encoded baseband receive signal, said quadrature demodulator/modulator circuit for modulating a transmit IF carrier frequency with a digitally encoded baseband transmit signal, an up converter circuit for receiving said modulated IF transmit signal from said quadrature demodulator/modulator circuit, and for converting said modulated IF transmit signal from IF to RF, wherein said up converter circuit outputs said modulated RF transmit signal to said power amplifier circuit in said Power Amplifier assembly, a synthesizer circuit comprising a first local oscillator circuit and a second local oscillator circuit, wherein said synthesizer circuit outputs a first local oscillator signal to an input of said up converter circuit and said down converter circuit, and wherein said synthesizer circuit outputs a second local oscillator signal to an input of said quadrature demodulator/modulator circuit.