Sharif Digital Repository

In order to improve the performance of radar systems, encouraging the movement towards multifunctional applications, wider frequency span is required to be considered for phased array systems constituting radars. The conventional approach of phase shifting is not applicable to wideband phased array system, and the need for phased array systems based on time delay is apparent. In active phased array systems where a transceiver module is placed before each radiating element, the task of controlling the delay and gain variation of each path is assigned to individual core chips residing in the transceiver modules. A typical core chip consists of several amplifying blocks along, with delay and... 

This thesis presents a four-antenna phased-array transceiver front-end for 5G applications. The designed front-end uses RF architecture and time division duplexing mode and operates in the 26~30 (GHz) band. In our design procedure, we have used a four-stage inductively degenerated common source LNA, a differential three-stage PA, and a vector-sum phase shifter. Circuit blocks are connected using traditional architecture, and an SPDT switch is used to determine the Tx/Rx mode of the system. A switching current reference is designed, which enables us to control the circuit gain over different process corners and temperatures.Each transmitter chain produces 13.42 (dBm) power at its operating... 

New applications such as high data rate telecommunications, millimeter-wave imaging systems, positioning systems, wall, and ground-penetrating radars, and vital sign monitoring radars require specifications of heavy-duty systems. In summary, in advanced applications with high bandwidth, having multiple inputs and multiple outputs, phased arrays, and optimal energy efficiency are in demand and desirable. Despite the diverse applications of these radars, commercial products in this field are very rare, expensive, and bulky. Therefore, research work in this area is justified from an applied perspective. Increasing the power amplifier's efficiency results in the creation of a smaller, more...