2011 IEEE 17 th International Symposium for Design and Technology in Electronic Packaging (SIITME) 978-1-4577-1277-7/11/$26.00 ©2011 IEEE 283 20-23 Oct 2011, Timisoara, Romania Influence of quantization errors on the develo of vector modulator based phaseshifter for u Smart Antenna applications Octavian Manu, Mihai Dimian, Adrian Graur Department of Computers, Electronics and Automations Ștefan cel Mare University of Suceava Suceava, România octavianm@eed.usv.ro Abstract— This paper presents the development of an advanced radiofrequency phase shifter operating on ultra-high frequency (UHF) band for use in phased antenna array or smart antenna applications. The proposedsolution is based on a vector modulator design which allows a phase change from 0 to 360 degree and also a variation of the gain between -3dB to -30dB. The frequency response of the vector modulator is between 700MHz and 1GHz, thus covering the UHF RFID band from 865MHz to 868MHz. The effects of quantization errors induced by the resolution of digital to analog converters used to drive the phaseshifter, over the phase shifts and gain variation, were analyzed. Keywords- phase shifter; vector modulator; phased antennas; smart antennas I. I NTRODUCTION Over the last years the development of phased antenna arrays and smart antenna received an increased interest due to the great potential [1] offered by these types of antennas in almost all types of applications ranging from localization and location estimation to communication services. The higher antenna gain, the increased signal to noise ratio, the increased Figure 1. Switched Beam Antenna Array spectral efficiency, the ability to track users faster th inertial system, the possibility of tracking multiple users a same time, spatial multiplexing are some of the antenna a characteristics which makes them very attractive to communications, localizations, radio-frequency identific (RFID) and wireless sensor networks (WSN) applications. Thus various techniques of beamforming and beam st were developed such as amplitude variance [2], phase var [3] or both phase and amplitude variance of the signal fee antenna array elements. The use of vector modulators [4] unlike the others types of phase shifters allows one to con phase, over the entire domain of 0 to 360 degree, and als modify the gain of signals fed to antenna array elements. presents the block diagram of a switched beam antenna a which has a set of predetermined beams, from which one time is being chose. The main disadvantage consists possibility that the user may not be in the center of beam. Adaptive antenna array presented on Fig. 2 can ge the radiation pattern dynamically such that the main oriented toward the desired user. These are more complic to build and more expensive than the switched beam type Figure 2. Adaptive Antenna Array This work was supported by European Framework Program 7 under the contract no. PIRG02-GA-2007-224904. O.M. thanks CNCSIS-UEFISCSU project number RU-107/2010 for the financial support.)