LNA, oscillator and mixer co-design for compact RF-CMOS ISM receivers

A co-design strategy for the implementation of a low-voltage fully integrated CMOS receiver is presented. This co-design approach allows the design of a compact direct-conversion receiver by avoiding 50 Omega matching buffers and networks, and AC coupling capacitors between mixer inputs and LNA and oscillator outputs. Moreover, the proposed circuit does not require DC choke inductors for mixer biasing. Since a 1.2 V power supply is used, a current bleeding technique is applied in the LNA and in the mixer. To avoid inductors and obtain differential quadrature outputs, an RC two-integrator oscillator is employed, in which, a filtering technique is applied to reduce phase noise and distortion. The proposed receiver is designed and simulated in a 130 nm standard CMOS technology. The overall conversion voltage gain is higher than 35.8 dB and the noise figure is 5.3 dB.