Heterodyne detection at 4 Gbit/s using a simple pin-HEMT receiver

A pin-HEMT receiver for multi-Gbit/s heterodyne detection systems is described. The receiver uses discrete, packaged devices and a simple hybrid construction to achieve a band-width of 10 GHz and a noise level not exceeding 13.5 pA/√(Hz). A sensitivity of −32.5 dBm is demonstrated at 4 Gbit/s using CP-FSK over 100 km of conventional single mode fibre.