Abstract: A dual feedback low noise amplifier includes a negative-feedback capacitive mutual-coupled common-gate amplifier of parallel-input parallel-output (PIPO) composed of a first transistor, a second transistor, a first coupling capacitor and a second coupling capacitor and a positive-feedback common-gate amplifier of parallel-input parallel-output (PIPO) composed of the first transistor, the second transistor, a first transformer and a second transformer. By means of dual feedback, the transconductance gain of the dual feedback low noise amplifier is increased, and the noise figure of the dual feedback low noise amplifier is decreased.

Abstract: A dual feedback low noise amplifier includes a negative-feedback capacitive mutual-coupled common-gate amplifier of parallel-input parallel-output (PIPO) composed of a first transistor, a second transistor, a first coupling capacitor and a second coupling capacitor and a positive-feedback common-gate amplifier of parallel-input parallel-output (PIPO) composed of the first transistor, the second transistor, a first transformer and a second transformer. By means of dual feedback, the transconductance gain of the dual feedback low noise amplifier is increased, and the noise figure of the dual feedback low noise amplifier is decreased.

Abstract: A frequency shift-keying reader circuit includes a band-pass filter, a low noise amplifier, a first balun, an injection-lock divide-by-2 frequency divider, a sub-harmonic mixer and a low-pass filter. The band-pass filter performs a filtering procedure to a radio frequency signal, wherein the filtered radio-frequency signal is received by the low noise amplifier to provide an injection signal, and the injection signal is received by the first balun to generate a first differential signal and a second differential signal. The injection signal is received by the injection-lock divide-by-2 frequency divider to provide a first oscillation signal and a second oscillation signal, wherein the first differential signal, the second differential signal, the first oscillation signal and the second oscillation signal are received by the sub-harmonic mixer for performing a mixing procedure and thereafter generating an output signal, the low-pass filter performs a filtering procedure to the output signal.

Abstract: A frequency shift-keying reader circuit includes a band-pass filter, a low noise amplifier, a first balun, an injection-lock divide-by-2 frequency divider, a sub-harmonic mixer and a low-pass filter. The band-pass filter performs a filtering procedure to a radio frequency signal, wherein the filtered radio-frequency signal is received by the low noise amplifier to provide an injection signal, and the injection signal is received by the first balun to generate a first differential signal and a second differential signal. The injection signal is received by the injection-lock divide-by-2 frequency divider to provide a first oscillation signal and a second oscillation signal, wherein the first differential signal, the second differential signal, the first oscillation signal and the second oscillation signal are received by the sub-harmonic mixer for performing a mixing procedure and thereafter generating an output signal, the low-pass filter performs a filtering procedure to the output signal.

Abstract: The present invention relates to an injection-locked RF receiver having trifilar transformer splitter. The injection-locked RF receiver includes a trifilar transformer splitter, an injection-locked oscillator and a phase detector. The trifilar transformer splitter includes a primary winding, a secondary winding and a tertiary winding. RF input signal is input to the primary winding. The secondary winding outputs a first differential signal to the injection-locked oscillator. The tertiary winding outputs a second differential signal to the phase detector. Using the trifilar transformer splitter of the invention, the frequency-shift keying demodulation with high sensitivity is achieved, and the number of amplifier can be reduced so as to lower the power consumption of the injection-locked RF receiver and reduce the complexity of the involved system.

Abstract: The present invention relates to an injection-locked RF receiver having trifilar transformer splitter. The injection-locked RF receiver includes a trifilar transformer splitter, an injection-locked oscillator and a phase detector. The trifilar transformer splitter includes a primary winding, a secondary winding and a tertiary winding. RF input signal is input to the primary winding. The secondary winding outputs a first differential signal to the injection-locked oscillator. The tertiary winding outputs a second differential signal to the phase detector. Using the trifilar transformer splitter of the invention, the frequency-shift keying demodulation with high sensitivity is achieved, and the number of amplifier can be reduced so as to lower the power consumption of the injection-locked RF receiver and reduce the complexity of the involved system.