Bandwidth extension for optical wireless receiver-amplifiers

A technique is presented which permits an enhanced frequency response for optical wireless receivers. A cascade bootstrap approach has been employed which has been combined with coil peaking to deliver a bandwidth improvement of around 7.2 times in comparison with a conventional high impedance front end. A PIN photodiode has been used as the detector, and the technique improve on the limitations normally incurred because of device capacitance, stray capacitance, and also transit time effects. As an example of the application of the method, an initial 236 MHz bandwidth high impedance front-end configuration is shown to be capable of a bandwidth of 1.7 GHz with the same gain. The noise penalty is compatible with the change in bandwidth, and not degraded by the bandwidth cubed factor which equalisation tends to produce for the same bandwidth extension.