Highly Packaged Terahertz Down-Converter Modules Using 3-D Integration

This letter describes the design of highly packaged heterodyne receivers for terahertz applications. The 3-D integration of a terahertz mixer with a low-noise intermediate frequency amplifier is implemented for the first time using off-the-shelf components. Thereby, an-order-of-magnitude volume and weight reduction are accomplished. We validate our packaging approach experimentally, demonstrating performance comparable to that of a similar receiver assembled with planar interconnects. These 3-D receivers can in principle constitute the basis of close-fitting, densely populated focal plane arrays.