Received: 8 December 2016 DOI: 10.1002/mop.30584 Switched beam patch array antenna using SPDT GaN HEMT switches Abdelaziz Hamdoun 1 | Mohammed Himdi 1 | Olivier Lafond 1 | Langis Roy 2 1 Institut d’Electronique et de T el  ecommunications de Rennes’ (IETR), University of Rennes 1, Rennes, France 2 University of Ontario Institute of Technology, Oshawa, Ontario, Canada Correspondence Abdelaziz Hamdoun, Institut d’Electronique et de T el  ecommunications de Rennes (IETR), University of Rennes 1, Rennes, France. Email: abdelaziz.hamdoun@univ-rennes1.fr Abstract In this article, a single-fed 4-panel 4 3 1 patch array antenna operating at 2.43 GHz with switched beam capability is pro- posed. The design allows the beam to be switched between 4 discrete directions giving 3608 coverage. The antenna beam is switched over the azimuth plane for U 5 08, U 5 908, U 5 1808, and U 5 2708. The beam control is achieved using GaN-based HEMT SPDT switches. Only 3 SPDT switches are integrated directly into the structure, allowing its nature to be electrically controlled over the desired 4 directions. Simu- lated and measured reflection coefficients and radiation patterns for the 4 cases are presented and discussed, showing good agreement. The antenna gain is around 3.8 dB includ- ing switches losses at 2.43 GHz. KEYWORDS GaN technology, SPDT switch topology, switched beam antenna 1 | INTRODUCTION Active integrated antennas (AIAs) are the subject of unprece- dented research along with growing interest for wireless systems applications. 1 The designs of AIAs are progressing toward oper- ating at multi-frequencies, scanning agile beams, and handling significant power levels, which has been a great challenge. For performing beam reconfigurable system, switched beam antenna is one of the emerging techniques 2 that is used to focus radiation toward a specific direction. In recent years, there has been increasing interest in the use of switched beam antennas in wireless communication systems. 3 Many advantages can be achieved by using this technique for modern reconfigurable communication systems, such as sufficient energy can be saved, noisy environments can be avoided, and power consumption can be reduced through increased antenna gain and reduce mul- tipath or interference. 4 There are several switch technologies available, including CMOS, 5 PIN diodes, 6 and GaAs devices. 7 However, active switches present some non-linear behaviors with high-power RF signals that influence antenna performance. As a result of advanced GaN-based high electron mobility transistor (HEMT) semiconductor devices with good linear- ity, 8 the designs of switched beam antennas with high-power handling capability and high-frequency operation are now achievable. Furthermore, reconfigurable AIAs, with high power/frequency and excellent efficiency, are in great demand for the future wireless communication systems. Moreover, Galium Nitride (GaN) is making inroads in base stations, mainly because it is a wide-bandgap technology, meaning that it is faster and provides higher breakdown vol- tages than silicon and other semiconductor devices. 9 In this article, a switched beam antenna is studied using dif- ferent oriented printed series-fed patch array antennas, where for the first time, GaN HEMT switches are used to choose the beam direction. The proposed switched beam antenna is designed to fulfill 2 basic requirements so as to demonstrate the feasibility of used GaN-based switch in switched beam antennas design and switching of antenna radiation pattern in different directions in azimuth with similar radiation pattern characteristics in the desired frequency band of operation. This design is proposed for applications at 2.43 GHz. 2 | GaN-BASED HEMTs SPDT SWITCH STRUCTURE The used single-pole-double-throw (SPDT) switches were implemented using coplanar waveguide GaN microwave monolithic integrated circuit (MMIC) technology established at the National Research Council (NRC), Canada. The pro- cess is based on an epilayer structure of AlGaN/GaN depos- ited on semi-insulating SiC substrates by MBE techniques. GaN500 NRC process with gate length of 0.5 lm has been used to manufacture the SPDT switch devices. The SPDT switch topology was first designed in ADS with lumped components that are constituting the model of a single switch in common gate configuration. This model has been described previously in ref. 10. The physical layout is 1558 | HAMDOUN ET AL.