An E-band Voltage Variable Attenuator Realised on a Low Cost 0.13um PHEMT Process

E-band spectrum at 71 to 76GHz and 81 to 86GHz offers worldwide availability and wide bandwidths under a light license system [1]. This makes it very attractive for very high data rate applications such as cellular back-haul. Component availability is currently relatively limited and cost relatively high [2] but this is starting to change. This paper describes the development of an E-band Voltage Variable Attenuator (VVA) realised on a low cost 0.13m gate length PHEMT process. The core VVA is a single-ended design that operates from a control voltage of between -2V and +0.6V. Simulated insertion loss is <1dB at 50GHz rising to 2.8dB at 90GHz. The E-band design uses two of the core circuit in a balanced configuration for improved return loss and increased linearity. It has an insertion loss of <4dB over 71 to 86GHz and a dynamic range of >30dB. Good performance is exhibited over an extended band of 50 to 90GHz. Devices are currently in fabrication and it is anticipated that measured results will be available in time for the presentation.