ADI’s HMC951 is a compact gallium arsenide (GaAs), monolithic microwave integrated circuit (MMIC), in-phase quadrature (I/Q) downconverter that operates from 5.6 GHz to 8.6 GHz. This device provides a small signal conversion gain of 13 dB with a noise figure of 2 dB and an image rejection of 32 dBc. The HMC951A uses a low noise amplifier (LNA) followed by an image mixer that is driven by a local oscillator (LO) buffer amplifier. The image reject mixer eliminates the need for a filter following the LNA and removes thermal noise at the image frequency. The IF1 and IF2 mixer outputs are provided and an external 90° hybrid is needed to select the required sideband. The I/Q mixer topology reduces the need for filtering of unwanted sideband. The HMC951A is a smaller alternative to hybrid style, single sideband (SSB) downconverter assemblies, and it eliminates the need for wire bonding by allowing the use of surface mount manufacturing techniques.

The HMC951A is available in 4 mm × 4 mm, 24-LFCSP and the HMC951B comes in a 24-QFN package. Both have an operating temperature range of -40°C to +85°C. Evaluation boards are available. The HMC951 is ideal for radios, radars, and electronic intelligence systems.