Complex filter based spectrum sensor for narrowband detection over a wide sensing bandwidth

This work introduces a complex filter based wideband spectrum sensor capable of narrowband detection. This work makes use of the band pass nature of the complex filter to achieve two objectives : i) Separation of upper sideband (USB) and lower sideband (LSB) around the local oscillator (LO) signal and ii) Resolution of smaller bands within a large detection bandwidth. The design is implemented in 130 nm mixed-mode CMOS RF process. The simulation results show a sensitivity of close to -50 dBm with image rejection ratio (IRR) close to 30 dB. The overall wideband detection bandwidth is 250 MHz which is partitioned into 40 MHz narrowband chunks with 6 such overlapping chunks.