10–30-Ghz Reflectionless Pseudo-Four-Path Mixer-First Receivers with Two-Phase LO

This article presents 10–30-GHz reflectionless pseudo-four-path mixer-first receivers. By introducing a balanced input network at the radio frequency (RF) port, the proposed receiver requires only a two-phase local oscillator (LO) to generate differential and orthogonal baseband (BB) signals, significantly reducing the complexity and power consumption of the LO generation circuit. The crosstalk issue caused by LO overlap is topologically mitigated by the inherent isolation (ISO) between the CPL and THU ports. In addition, the balanced input network not only maintains the reflection-based out-of-band (OOB) rejection mechanism of the $N$ -path mixer-first receiver but also enables a reflectionless design. To further improve the transition-band roll-off and OOB rejection, two pairs of transmission zeros flanking the passband are introduced. The first pair of close-in transmission zeros is generated by an improved blocker-canceling technique, whereas the second pair is introduced by the $LC$ tanks. Benefiting from the balanced input network and the improved blocker-canceling technique, both the input matching and OOB rejection are decoupled from the switch size, enabling the use of small-sized switches and thereby achieving high LO-to-RF ISO. Two receiver versions (Design-1 and Design-2) are presented: Design-1 excludes $LC$ tanks, whereas Design-2 incorporates $LC$ tanks. Fabricated in a low-cost 130-nm CMOS SOI process, both designs achieve a transition-band roll-off of approximately 40 dB/decade. Across 10–31 GHz, Design-1 achieves an RF-to-BB conversion gain of 7.3–10.3 dB, a double-sideband (DSB) noise figure (NF) of 12.1–16.3 dB, a blocker 1-dB compression point (B ${}_{\mathbf {1dB}}$ ) of 2.15 dBm, an OOB input-referred third-order intercept point (IIP ${}_{\mathbf {3}}$ ) of 11.3 dBm, an OOB rejection exceeding 25 dB, and an LO-to-RF ISO of 38–56.5 dB. Operating across 10–30 GHz, Design-2 exhibits 7.7–10.7-dB RF-to-BB conversion gain, 11.9–16.2-dB DSB NF, 3.15 dBm B ${}_{\mathbf {1dB}}$ , 12.1-dBm OOB IIP ${}_{\mathbf {3}}$ , >29-dB OOB rejection, and 36.9–61.7-dB LO-to-RF ISO. The maximum power consumption of both designs is below 36.2 mW.