Experimental RF transceiver design for W-CDMA user equipment

Abstract

The $3^{rd}$ generation cellular system, W-CDMA system that adds broadband data to support video, Internet access, and other high-speed services is being stated. The service is to offer seamless wideband services across a variety of environments. As is typical for mobile communication systems standardization, sufficient RF performance has been assumed and most efforts have been put to digital baseband issues. This is especially true for the mobile phone transceivers, but the RF part is still the bottleneck of the entire system. So, in the RF concept engineering of today``s commercial products, an accurate prediction of the needed RF performance by using RF system simulation is indispensable. In this thesis, an experimental RF transceiver has been designed and built on printed circuit board (PCB) for a FDD mode W-CDMA user equipment. To accomplish this work, systematic design procedure with top-down approach from system level to circuit level was used. At first, RF transceiver standard in 3G TS 34.121 [4] for W-CDMA is analyzed and RF specifications are extracted by using receiver noise equation for receiver and spectrum emission requirement for transmitter. Then from the system specification, total transceiver is simulated and designed. To implement RF circuits of building blocks, various consideration for circuit design on PCB are discussed. The equivalent model to interface fixture like SMA connector and microstrip line are constructed and verified. Then, RF building blocks are simulated and implemented with off-the-shelf commercial components based on de-embedding procedure by using the equivalent model to interface fixture. Finally, the building blocks are measured and from the measured data, performances of receiver and transmitter are analyzed. The evaluated receiver has dynamic range of 90 dB, NF of 6.9 dB and IIP3 of -12 dBm. And transmitter has dynamic range of 88 dB, maximum output power of 23.8 dBm. So, these results satisfy almost the system requi...