A 7–15 GHz IF Reflectionless Receiver with Tri-Coupled Transformer Based LNA and 43.8–76.3 ns Settling Time Automatic Gain Control

This paper presents a 7–15 GHz IF reflectionless receiver featuring wide operating bandwidth and fast automatic gain control (AGC). The IF reflectionless amplifier (IFRA) absorbs out-of-band reflected signals to suppress the intermodulation interference, thereby achieving flat response and improving the precision of post-stage AGC. The noise self-canceling LNA is implemented with tri-coupled transformer (XFMR) to extend the bandwidth. A dual-stage AGC achieves high accuracy and fast gain control through two feed-forward loops. Verified in a conventional 40-nm bulk CMOS technology, the proposed receiver achieves a 7–15 GHz RF bandwidth with 2.2 GHz baseband bandwidth. The dB-linear gain error over 25 dB gain range is within ±1 dB. The proposed receiver attains the settling time of 43.8–76.3 ns, a noise figure (NF) of 10.6 dB, and an OP1dB of 3.8 dBm. Meanwhile, it supports 500 MHz 64-QAM modulation and 8-channel 100 MHz 64-QAM carrier aggregation.