A
high data rate communication
system operating at frequencies greater than 70 MHz and at data rates of about 1.25 Gbps or greater. Preferred embodiments include modulators with a resonant
LC circuit including a
diode which is back-biased for "off" (i.e., no transmit) and forward biased for "on" (or transmit). The modulator is a part of high performance transceivers for
wireless,
millimeter wave communications links. A preferred embodiment provides a
communication link of more than eight miles which operates within the 71 to 76 GHz portion of the
millimeter spectrum and provides
data transmission rates of 1.25 Gbps with bit error rates of less than 10<-10 >. A first
transceiver transmits at a first bandwidth and receives at a second bandwidth both within the above spectral range. A second
transceiver transmits at the second bandwidth and receives at the first bandwidth. The transceivers are equipped with antennas providing
beam divergence small enough to ensure efficient spatial and directional partitioning of the data channels so that an almost unlimited number of transceivers will be able to simultaneously use the same spectrum. In a preferred embodiment the first and second spectral ranges are 71.8+ / -0.63 GHz and 73.8+ / -0.63 GHz and the half power beam width is about 0.2 degrees or less. Preferably, a
backup transceiver set is provided which would take over the link in the event of very
bad weather conditions. In other embodiments especially useful for mobile applications at least one of the transceivers include a GPS locator.