Schottky Heterodyne Receivers With Full Waveguide Bandwidth

Goddard Space Flight Center, Greenbelt, Maryland

Compact THz receivers with broad bandwidth and low noise have been developed for the frequency range from 100 GHz to 1 THz. These receivers meet the requirements for high-resolution spectroscopic studies of planetary atmospheres (including the Earth’s) from spacecraft, as well as airborne and balloon platforms. The ongoing research is significant not only for the development of Schottky mixers, but also for the creation of a receiver system, including the LO chain.

Figure 1. **Measured Performance** of a WR-1.9 (400–600 GHz) subharmonic mixer (shown in inset).

The new receivers meet the goals of high sensitivity, compact size, low total power requirement, and operation across complete waveguide bands. The exceptional performance makes these receivers ideal for the broader range of scientific and commercial applications. These include the extension of sophisticated test and measurement equipment to 1 THz and the development of lowcost imaging systems for security applications and industrial process monitoring. As a particular example, a WR-1.9SHM (400–600 GHz) has been developed (see Figure 1), with state-of-the-art noise temperature ranging from 1,000–1,800 K (DSB) over the full waveguide band. Also, a Vector Network Analyzer extender has been developed (see Figure 2) for the WR1.5 waveguide band (500–750 GHz) with 100-dB dynamic range.