COMPARATIVE ANALYSIS OF SPST AND SPDT RF SWITCHES EMPLOYING FIELD-EFFECT-BASED TRANSISTORS FOR FUTURE WIRELESS COMMUNICATION

Abstract

In this modern technology era, the usage of smartphones are important for human’s life due to their multifunction purposes. For instance, wifi, Bluetooth, GPS are now being integrated in mobile phone to send email, text and voice messages. These applications operate in different frequency spectrums. Hence, the switches are important to ensure smooth transition between these frequencies. Traditionally, the basic switch circuit consists of either diodes or FETs. In this project, pseudomorphic high electron mobility transistors (pHEMTs) are used to design the switches. pHEMT is a part of FETs family with the advantage of high switching capability. The analysis started with a performance comparison between pHEMT and p-i-n diode. The results showed that pHEMT switches produced better performance in term of isolation and insertion loss. Further analyses are done using pHEMT configuration where several parameters such as series/parallel configuration, gate fingers and gate widths are varied. The performance of the switches can be improved by increasing the number of gate widths and gate fingers. However, the performance of the switches for series and parallel switches configurations depend on their circuit arrangements either in combination or multistage circuits. Finally, the optimized designs of both SPST and SPDT switches are compared with the existing research.