This paper demonstrates an optically controlled Co-Planar Waveguide (CPW) switch operating in the millimetre wave region. Full wave electromagnetic analysis used a multi-layer model to simulate the photoinduced plasmas and good agreement between measured and simulated results has been achieved. The insertion loss is less than 4dB and isolation is greater than 15dB from 32GHz-50GHz. This approach requires the use of 175mW of optical power at a wavelength 980nm, but it removes the need for bandwidth limiting electrical bias networks. Index Terms-Optically induced plasmas (OIP), Co-Planar Waveguide (CPW), millimeter wave (mmW), optical switch

This paper presents a highly linear optically reconfigurable microwave switch with high power handling ability. A silicon superstrate with bottom illumination is employed. A transparent substrate is used and two different microstrip gap distances are characterized by two-tone nonlinearity measurement with different tone spacings and optical powers. A maximum third order intercept point referred to input power of +78.5dBm has been obtained and the maximum microwave power tested was over 30W per tone close to 2 GHz. Thermal imaging has been used to observe the device hot-spots as a function of RF power.

A novel, high power optically controlled microwave switch is presented. The switch uses integrated illumination of a silicon superstate through a low loss glass substrate which reduces losses related to the plasma conductivity tail in the silicon. Numerical electromagnetic modelling is used to design the switch and good agreement between measured and simulated results has been achieved. The switch is then characterised using a two-tone non-linearity test at 2GHz and a third order intercept point of +72dBm is obtained with 10W per tone.

A photoconductive grounded coplanar waveguide (GCPW) millimeter-wave switch controlled by a single infrared light emitting diode (LED) is presented. By converting a straight GCPW transmission line into an alternating steppedimpedance line structure, the proposed device shows an on-state insertion loss of less than 2.9 dB and an off-state isolation of more than 15 dB over a wide frequency range of 12-30 GHz, with a particularly good RF performance in the K band (18-27 GHz). The required optical power and electrical power of the switch are only 199 mW and 364 mW, repectively. This device also demonstrates an absorptive characteristic with a low reflection coefficient of less than-13.5 dB within this frequency range for both the on and off states. In addition, by employing through-holes for illumination of a silicon superstrate, the proposed device can be fabricated with rapid and low-cost laser-etching and can be easily integrated with other microwave and millimeter-wave circuits.