antenna was optimized to achieve the highest performance possi- ble on real electromagnetic environment. Presented results of return loss, peak gain and radiation patterns show very good per- formance. The developed antenna operates in all European and American LTE bands, comprising a total bandwidth from 698 to 2700 MHz at 26 dB of return loss. Obtained values of efficiency and average gain are included as key parameters needed to design antennas in mobile communications, giving an average gain between 211.8 and 27.21 dB, and adequate TRP and TIS values for the whole band. SAR testing simulations are also presented complying with current body mount FCC regulations. For further work, the proposed antenna can be simulated with a final wrist worn application, adding esthetic plastics, soft and light memory foam material for comfort, fine tuning with battery-LCD, and so forth. Utilize the second wing space for a MIMO system or use that space for a standalone WIFI and GNSS antennas. Analyze the option to adapt the antenna with tunable technology to compensate body loading effect. ACKNOWLEDGMENT The authors would like to thank CONACYT for the financial support. REFERENCES 1. R. Van der Meulen, In: IoT expo and symposium 2015, Gartner, Inc., Newsroom, Barcelona, Spain, November 2015. 2. S. Su and Y. Hsieh, Integrated metal-frame antenna for smartwatch wearable device, IEEE Trans Antennas Propag 63 (2015). 3. W. Chen, C. Yang, and W. Sin, MIMO antenna with Wi-Fi and blue- tooth for smart watch applications, In: IEEE MTT-S 2015 International Microwave Workshop Series, Taipei, September 2015, pp. 212–213. 4. X. Gao et al., A novel wrist wear dual-band diversity antenna, In: Antennas and Propagation Society International Symposium, Charleston, SC, June 2009, pp. 1–4. 5. Apple, Inc., View countries with supported LTE networks, Available at: http://www.apple.com/iphone/LTE 6. A. Boryssenko, Taxonomical and heuristic studies on UWB antenna design strategies, High Frequency Electron 8 (2009). 7. K. Wong, Planar antennas for wireless communications, 1st ed., Wiley, Hoboken, NJ, 2003. 8. B. Jordan, PCB design, A guide book for designers, Altium, 2013. 9. Schmid & Partner Engineering AG, Speag, SHO Forearm Phantom V2, SHO-LFPV2, target dielectric parameters, CTIA, Over the Air Performance, Rev. 3.5.2, September 2015. 10. G. Kumar and K. Gupta, Directly coupled multiple resonator wide- band microstrip antennas, IEEE Trans Antennas Propag 33 (1985). 11. H.N. Mayrovitz, X. Guo, M. Salmon, and M. Uhde, Forearm skin tissue dielectric constant measured at 300 MHz: Effect of changes in skin vascular volume and blood flow, Clin Physiol Funct Imaging 33 (2012), 55–61. 12. 447498 D01 General RF Exposure Guidance v06, Mobile and Porta- ble Device RF Exposure Procedures and Equipment Authorization Policies, Office of Engineering and Technology Laboratory Division, Federal Communication Commission, October 2015. 13. E. Lillie, J.E. Urban, S.K. Lynch, A.A Weaver, and J.D. Stitzel, Evaluation of skull cortical thickness changes with age and sex from computed tomography scans, Injury Biomechanics Research, Virgin- ia Tech, June 2013. 14. Murata, Ltd., LTE noise problems, Available at: http://www.murata. com/en-us/products/emc/emifil/ knowhow/lte/chapter01#sec2 15. Sierra Wireless, Inc., Product Technical Specification & Customer Design Guidelines AirPrime MC7354”, Ver 7, March 2015. 16. AT&T, Corp., OTA Requirements Summary, Document #13340, Revision 5.5, March 2014. VC 2017 Wiley Periodicals, Inc. SIMPLE LOW PROFILE DUAL POLARIZED PLANAR ANTENNA ARRAY Ka Ming Mak, 1 Hau Wah Lai, 1 and Kwai Man Luk 2 1 State Key Laboratory of Millimeter Waves, City University of Hong Kong, Hong Kong SAR; Corresponding author: kammak@cityu.edu.hk 2 Department of Electronic Engineering, City University of Hong Kong, Hong Kong SAR Received 27 September 2016 ABSTRACT: A simple dual polarized circular slot antenna array for satellite TV is proposed in this letter. The antenna array consists of sixteen elements and each of them is excited by an olive-shaped feeding probe. The proposed antenna array has measured gains of 18 dBi for both polarizations and an input ports isolation excess 30 dB. The anten- na can totally cover the bandwidth of the TV satellite application, which is from 11.7 to 12.2 GHz. The antenna is also very low profile, which is much thinner than other conventional stripline-fed planar array anten- nas. VC 2017 Wiley Periodicals, Inc. Microwave Opt Technol Lett 59:783–786, 2017; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.30392 Key words: antenna arrays; antenna feeds; dual polarization; micro- strip transmission line; slot antennas In 1982, Rammos proposed a methodology to design high gain and high efficiency planar antenna array for both linear [1] and dual [2,3] polarizations. For 12 GHz satellite TV reception, a circularly polarized antenna is required. It can be simply dephasing two linear orthogonal polarized signals of a dual polarized antenna for receiving left- or right hand circular polar- izations. The antenna consists of four layers for linearly polari- zation and seven layers for dual linearly polarization. In 1991, a similar structure was reported by Zaghloul and Sorbello [4] that the radiating element could be a slot or patch. The methodolo- gies for exciting circular polarization were also illustrated in the patent. In 2006, the antenna structure was modified to provide multiple frequency band operation [5]. An ultra-wide band antenna with similar geometry of the single element without back cavity was presented in 2009 [6]. Years after, a circularly polarized cavity-backed circular slot antenna fed by microstrip line was presented by Hu et al. [7]. The above literature demon- strated that the planar antenna array design by Rammos [1] is still very practical due to its attractive characteristics even it was invented over thirty years ago. Based on the design in Ref. [1], a four by four microstrip line-fed dual polarized antenna array is presented in this letter. Even though the gain of the proposed antenna is lower than the designs in Refs. [2,3] by about 3 dB, the total height of the pro- posed antenna is only half of that of the linear polarized antenna in Ref. [1] and should be much lower than that of the dual polarized antenna in Refs. [2,3]. The novelties of the proposed design are simpler feed network structure, lower profile, and lighter weight. A 16 element array antenna was fabricated and measured to demonstrate the feasibility of the proposed design. The measured results are in good agreement with the computa- tional prediction. 1. ANTENNA CONFIGURATION Figure 1 shows the configuration of the design. The pro- posed antenna array is composed of two identical printed DOI 10.1002/mop MICROWAVE AND OPTICAL TECHNOLOGY LETTERS / Vol. 59, No. 4, April 2017 783