A Low-Power, Subharmonic Super-Regenerative Receiver toward a
Massive Multichannel FMCW Radar Close to Cut-Off Frequency
This paper reports for the first time on an
entirely new subharmonic super-regenerative receiver (SRR)
concept. Unlike in conventional SRRs, the local oscillator
signal is additionally used for non-linear downconversion,
enabling phase-coherent amplification. An experimental concept
verification is done with a 24 GHz FMCW radar transceiver
implemented using planar microstrip technology. It is shown that
the subharmonic SRR down-conversion allows to significantly
increase the maximum operating frequency and bandwidth.
In addition, the LO power requirements are considerably
reduced compared to what is typically needed in passive mixer
approaches. Operated with a sinusoidal quench signal, the
fabricated SRR achieves a gain greater than 60 dB with a power
consumption of only 24mW. It is explained that the concept
allows also for operation near the semiconductor cutoff frequency.
This novel concept is especially suited for scaling to integrated circuits with a high
number of receive channels at very high carrier frequencies.