Handheld microwave radiometer for education and outreach

This investigation features a low-cost (<$100) 1.413-GHz handheld microwave radiometer for use in educating students about microwave radiometry. The microwave radiometer presented is a conventional Dicke radiometer, but fabricated on low-cost printed-circuit board (PCB) material using inexpensive commercial off-the-shelf (COTS) parts. The instrument antenna is a rectangular horn fed by a stacked-patch probe-fed element. With a total weight of just about 2 kg (4 lbs) and a targeted overall cost of under US$100, the handheld radiometer presents several educational potentials in Earth and Sun science applications: primarily as a handy scientific tool for surface soil moisture measurements, and secondarily as a miniature solar radio telescope.