Multi-Stack Quantum Barrier varactor frequency tripiers, an efficient way for mm-wave power generation

Constantly growing market of commercial mm-wave applications such as Indoor Wireless Links, Automotive Radars etc., require the development of new efficient and cost effective integrated power sources. Frequency multipliers based on Schottky diodes and FET transistors have dominated this field of application. However, the necessity of bias and Idlers circuits in the above mentioned multipliers make them difficult to realise especially at mm-waves. A new class of symmetrical characteristics diodes such as the Multi-Stack Quantum Barrier Varactor (MSQBV) require no bias nor idlers and generate only odd harmonics of the input frequency. This make them very attractive for applications as mm-wave frequency tripiers. The MSQBV is a hetero-structure GaAs/InP composite material. The barrier region is made of high band gap materials and is sandwiched between two lightly doped regions. The contacts at the top and bottom of the device are of Ohmic type. The whole structure acts as a variable capacitance with symmetrical response around zero bias voltage. In this paper, recent results in the development of MSQBV based frequency tripiers at mm-wave are presented.