Status and Prospects of High-Power Heterostructure Barrier Varactor Frequency Multipliers

Abstract

| There is a high demand for compact, roomtemperature sources operating at millimeter-wave and terahertz (THz) frequencies for space instruments and terrestrial applications. This part of the electromagnetic spectrum is by far the least explored because of the difficulty of generating energy at these frequencies. Continuous-wave oscillators based on either electronics or photonics are limited in output power for fundamental reasons. Varistor and varactor frequency multipliers have shown outstanding performance in terms of output power, but further technical development will be essential to solve the lack of efficient and compact terahertz sources. In this paper, we present the status of heterostructure barrier varactor (HBV) diode frequency multipliers. The performance and prospects for THz applications in which HBV diode technology can offer advantages over conventional solutions are discussed. For instance, such a device can be easily scaled by increasing the number of barriers to produce and handle higher power. The inherent symmetry confines the power generation to odd harmonics, thereby simplifying the design of high-order frequency multipliers. For example, highpower triplers ( × 3 ), quintuplers ( × 5 ), nonlinear transmission lines (NLTLs) and grid multipliers utilizing HBV diodes are presented. Overall, HBV technology is a natural stepping stone from high-power microwave amplifiers to higher frequencies and can both simplify and improve the performance of terahertz sources.

A Frequency Multiplication Method Based on Extracting Harmonic From Narrow Pulse

“…The varactor diode multiplier generally consists of an inputoutput matching circuit, a filter circuit, an idle circuit and a bias circuit. Although power and efficiency of the varactor frequency multiplier are relatively large, the circuit structure of frequency multiplier is relatively complex and difficult to debug [22]- [24].…”

Гетеробарьерные Варакторы С Неоднородно Легированными Модулирующими Слоями

“…Эпитаксиальные гетероструктуры современных ГБВ, как правило, выращиваются методом молекулярнопучковой эпитаксии (МПЭ) на подложках InP и содержат несколько нелегированных барьерных слоев InAlAs/AlAs/InAlAs, расположенных между однородно легированными модулирующими слоями InGaAs n-типа [2]. ГБВ на основе таких гетероструктур успешно используются при создании трехкратных и пятикратных умножителей частоты с уровнем непрерывной выходной мощности от сотен mW в частотном диапазоне около 100 GHz до единиц mW на частотах вблизи 50 GHz [3]. Одним из ключевых требований к структурам ГБВ является низкий уровень тока утечки при напряжениях, соответствующих максимальной амплитуде входного сигнала.…”

Low noise 874 GHz receivers for the International Submillimetre Airborne Radiometer (ISMAR)

“…A key feature of the HBV is the voltage dependent capacitance, which has its maximum at zero voltage. 23 This in turn results in a component that can operate without biasing. A conversion efficiency of 23% with a maximum input power of 800 mW over a 15% 3-dB bandwidth has been reported for these components.…”