One embodiment is a reconfigurable mixer topology for selectively implementing one of a harmonic rejection mixer (HRM) and a subharmonic mixer (SHM), the reconfigurable mixer topology comprising a mixer core comprising a plurality of differential mixers each having a first clock input and a second clock input; a clock generator for generating a plurality of clock signals each having a different phase; and a clock distributor for distributing the plurality of clock signals to the first and second clock inputs of the differential mixers in accordance with a designated operation of the reconfigurable mixer as an HRM or an SHM.

A negative capacitance circuit is connected between a drain and a source of the mixer transistor. With this configuration, the negative capacitance circuit is connected in parallel to a parasitic capacitance generated between the drain and the source of the mixer transistor, and the parasitic capacitance can be canceled out in a wide band by the negative capacitance circuit connected in parallel.

A source injection mixer includes an FET, an IF matching circuit between an IF port and a gate of the FET, and that matches impedance of the IF port and impedance of the gate as viewed from the IF port, a shorting stub of which one end is connected to a source of the FET and another end is grounded, and shorter than ¼ of an electric length at a frequency of LO signals, an LO matching circuit between an LO port and the source of the FET, and that matches impedance of the LO port and impedance of the source as viewed from the LO port, and an RF matching circuit between an RF port and a drain of the FET, and that matches impedance of the RF port and impedance of the drain as viewed from the RF port.

The present disclosure provides a super-regenerative transceiver with a feedback element having a controllable gain. The super-regenerative transceiver utilizes the controllable gain to improve RF signal data sensitivity and improve RF signal data capture rates. Super-regenerative transceivers described herein permit signal data capture over a broad range of frequencies and for a range of communication protocols. Super-regenerative transceivers described herein are tunable, consume very little power for operation and maintenance, and permit long term operation even when powered by very small power sources (e.g., coin batteries).

The present disclosure provides a super-regenerative transceiver with a feedback element having a controllable gain. The super-regenerative transceiver utilizes the controllable gain to improve RF signal data sensitivity and improve RF signal data capture rates. Super-regenerative transceivers described herein permit signal data capture over a broad range of frequencies and for a range of communication protocols. Super-regenerative transceivers described herein are tunable, consume very little power for operation and maintenance, and permit long term operation even when powered by very small power sources (e.g., coin batteries).

A room-temperature semiconductor maser, including a first matching network, a second matching network, a heterojunction-containing transistor, and a resonant network. The output end of the first matching network is connected to the drain of the heterojunction-containing transistor. The input end of the second matching network is connected to the source of the heterojunction-containing transistor. The gate of the heterojunction-containing transistor is connected to the resonant network. The pumped microwaves are fed into the input end of the first matching network.

The present disclosure provides a frequency-converting super-regenerative transceiver with a frequency mixer coupled to a resonator and a feedback element having a controllable gain. The frequency-converting super-regenerative transceiver utilizes the frequency mixer to shift the incoming frequencies, based on a controlled oscillator, to match the frequency of operation of the super-regenerative transceiver. The frequency-converting super-regenerative transceivers described herein permit signal data capture over a broad range of frequencies and for a range of communication protocols. The frequency-converting super-regenerative transceivers described herein are tunable, consume very little power for operation and maintenance, and permit long term operation even when powered by very small power sources (e.g., coin batteries).

A balanced magnetoresistive frequency mixer comprises a first spiral coil, a second spiral coil, a balanced magnetoresistive sensor bridge, and a magnetic shielding layer. The coils are located between the magnetic shielding layer and the sensor bridge. The sensor bridge comprises a magnetoresistive full bridge consisting of four bridge arms and a balancing bridge arm connected to the power supply end of the full bridge. The four bridge arms contain pairs located in a first sub region and a second sub region above or below the first spiral coil, the balancing arm is located in a third sub region above or below the second spiral coil, a first frequency signal is input into the first spiral coil, a second frequency signal is input into the second spiral coil, and a frequency-mixed signal is output from a signal output end of the full bridge.

The present disclosure provides a frequency-converting super regenerative transceiver with a frequency mixer coupled to a resonator and a feedback element having a controllable gain. The frequency-converting super-regenerative transceiver utilizes the frequency mixer to shift the incoming frequencies, based on a controlled oscillator, to match the frequency of operation of the super-regenerative transceiver. The frequency-converting super-regenerative transceivers described herein permit signal data capture over a broad range of frequencies and for a range of communication protocols. The frequency-converting super-regenerative transceivers described herein are tunable, consume very little power for operation and maintenance, and permit long term operation even when powered by very small power sources (e.g., coin batteries).

Tunable filters, cancellers, and duplexers based on passive mixers. A tunable delay cell includes passive mixers electrically coupled together for receiving an input signal and outputting a delayed signal, each passive mixer comprising a plurality of mixer switches. The tunable delay includes a control circuit for providing, to each passive mixer, a respective plurality of local oscillator (LO) signals, one to each mixer switch of each passive mixer. The control circuit is configured to vary the LO signals to cause a target frequency band of the input signal to be delayed by a target delay time in propagating through the passive mixers.