Wideband bidirectional MMIC amplifiers for new generation T/R module

Switchless bidirectional amplifier for wireless communication systems

“…There, bidirectional amplifiers realized as monolithic microwave integrated circuits (MMIC) bias a transistor circuit in such a way that it amplifies either in the one or the other direction. Full-duplex bidirectional amplifiers are presented for instance in [5][6][7][8]. In [5] a transistorized-directional coupler and in [6] a microstriplinedirectional coupler is used to combine two amplifiers for fullduplex applications.…”

“…However, a transistorized-directional coupler shows a high noise and can handle only low power, and microstripline-directional couplers become too big for some applications. In [7,8] distributed amplifiers are used to obtain a bidirectional effect without switching. Those amplifiers show high noise and low power handling capacity.…”

Compact RF front-end configuration for short-range communication

“…The use of two individual T=R paths has the advantage of achieving optimum designs for each path and result in an improved communication range and quality. However, they also suffer the disadvantages of more circuit components, more complicated circuit layout, and higher cost [1][2][3]. Owing to the dramatic increase of wireless personal communication requirements in recent years, many new transceiver architectures have been proposed to simplify the circuit configuration and to reduce the system cost.…”

“…Thus, the circuit performance can be somewhat sacrificed in order to obtain a compact and low-cost circuit configuration. Tsukii et al [1] and Archer et al [3] presented singlepath transceiver architectures using a switched bidirectional amplifier (BDA). The transmitting and receiving signal share the common RF circuits so as to simplify the circuitry.…”

A novel bi-directional amplifier with applications in active van atta retrodirective arrays

“…Although several investigations have reported on designing bi-directional amplifiers [14], [15], they are not suitable for use in active retrodirective antenna arrays. This is because the amplification direction of these amplifiers was controlled by switches and, thus, the amplifiers could not simultaneously function in both directions.…”