Design a new type of active quasi circulator module

A HBT‐based quasi‐circulator with wideband equalization technique

“…The RF front‐end circuit components will therefore be fewer, smaller, and more importantly transparent to changing standards such as the proposed future wideband/multiband RF architecture based on software defined radios. Active quasi‐circulators based on DA theory have been proposed and gave wideband performance [2–4] compared with previous limited bandwidth structures. All these active quasi‐circulator's structures [2–4], however, were constructed using FETs.…”

“…Active quasi‐circulators based on DA theory have been proposed and gave wideband performance [2–4] compared with previous limited bandwidth structures. All these active quasi‐circulator's structures [2–4], however, were constructed using FETs. Because of the heterojunction bipolar transistor (HBT)‐based DAs offering bandwidth and output power advantages, it has been adapted for design of DAs [5, 6].…”

Design of three new types of active quasi‐circulator modules

“…In this design, the frequency response was extended to 2.1 GHz, and also the insertion loss and isolation are reported as 6 and 18 dB, respectively. In [4], using line-unified FETs has been proposed that can operate over a wide frequency range (1)(2)(3)(4)(5)(6)(7)(8)(9)(10). This circuit consists of an active out-of-phase divider and an active in-phase combiner.…”

“…In a recent article [8], the authors introduced a new structure of an active QCM that consists of one type unilateral amplifiers and showed that the proposed circuit was simpler and more efficient than the other reported modules. Now improving and extending that work, in this article, they present two other configurations of active QCMs that use unilateral out-of-phase divider/combiner.…”

Projeto e análise de aplicações de circuladores ativos para a operação em frequências de ultrassom Doppler de ondas contínuas

“…É muito comum a modelagem de circuladores pelas matrizes de espalhamento. De acordo com as características dos circuladores vistas na Seção 2.1, as matrizes de circuladores e quasicirculadores ideais são descritas, respectivamente, nas matrizes de espalhamento 2.8a e 2.8b (Bahri et al, 2008).…”