A FG-CPW single balanced diode mixer

In this paper, an FG-CPW (Finite-Ground Coplanar Waveguide) balanced diode mixer is presented. Frequency bandwidth is selected for a C-band, which is 5.72/spl sim/5.82 GHz for RF, 5.58/spl sim/5.68 GHz for LO, and 140 MHz for IF signals. A rat-race hybrid is designed for the accomplishment of single balanced type mixers. A low pass filter (LPF) with CPW structure is used for good conversion loss and unwanted harmonics suppression. When an LO signal with the power of 4 dBm at 5.635 GHz is injected, a conversion loss of 6.2 dB is obtained for the mixer. Also, LO to RF and LO to IF isolation of 30 dB and 40 dB are obtained, respectively. This mixer can be used in wireless LAN applications.