An LMDS, subharmonically pumped image reject mixer

In this paper we present a 25-34 GHz subharmonically pumped image reject mixer (IRM). This is to the author's knowledge the first detailed report of a subharmonic IRM MMIC in this frequency band (Smith and Novak, 1998). It directly addresses the LMDS frequency band, and also 26 GHz and 28 GHz point to point radio applications. The IRM has a conversion loss of 11dB, an image rejection of 22-24 dB and an input IP3 of +17 dBm. To further reduce the required MMW system complexity, an on-board LO amplifier has been included reducing the required LO drive to 2 dBm while drawing only 28 mA at 4 V. Due to lumped element matching throughout, the design occupies only 2.28 mm/sup 2/ of GaAs area.