Transistor package leads form quarter-wave antenna elements that directly
radiate RF energy into free space without the need for a separate
antenna. The transistor operates at a fundamental frequency and radiates
a harmonic, thereby allowing radiation at frequencies normally considered
"beyond cutoff" for a packaged transistor. This technique enables an
additional 20 GHz of spectrum for use by surface mount technology. The
transistor may be mounted on 1.6 mm thick glass-epoxy circuit board that
also forms a quarter-wave reflector at 26 GHz. An optional dielectric
lens produces a narrow beam and an optional planar filter rejects
spurious fundamental emissions. A 26 GHz ultra-wideband (UWB) pulse-echo
radar rangefinder implementation provides a low-cost upgrade to
ultrasound.