[7] CheongWu PK, Choi WW, Tam KW. Yagi-Uda antenna for mul- tiband radar applications. IEEE Antennas Wireless Propag Lett. 2014;13:1065–1068. [8] Khan OM, Islam ZU, Islam QU, Bhatti FA. Multiband high-gain printed Yagi array using square spiral ring metamaterial structures for s-band applications. IEEE Antennas Wireless Propag Lett. 2014;13:1100–1103. How to cite this article: Tirado-Mendez JA, Jardon- Aguilar H, Flores-Leal R, Rangel-Merino A, Linares- Miranda R. Multiband microstrip yagi-uda antenna based on drivers stack configuration. Microw Opt Tech- nol Lett. 2018;60:1211–1215. https://doi.org/10.1002/ mop.31133 Received: 7 October 2017 DOI: 10.1002/mop.31132 Wideband dual-bandpass 0.18-mm CMOS SPDT switch utilizing dual-band resonator concept Youngman Um | Cam Nguyen Department of Electrical and Computer Engineering, Texas A&M University, College Station, Texas 77843 Correspondence Youngman Um, Department of electrical and Computer Engineering, Texas A&M University, 3128 TAMU, College Station, Texas, USA. Email: youngman.um@tamu.edu Funding information NPRP grant, Qatar National Research Fund (a member of Qatar Foundation), Grant/Award Number: 6-241-2-102 Abstract A fully integrated wideband concurrent dual-band single- pole double-throw (SPDT) switch with integrated dual- band band-pass filtering has been developed over two wide bandwidths around 24 and 60 GHz in a 0.18-mm SiGe BiCMOS process. The developed concurrent dual- wideband SPDT switch is configured to make it approxi- mately equivalent to a dual-band resonator in the on-state operation. It exhibits measured insertion losses and isola- tions of 5.4 and 31.4 dB, and 5.2 and 16.5 dB at 24 and 60 GHz, respectively. The measured peak stop-band rejec- tion between the two pass-bands is 26 dB at 42.3 GHz. With single-tone 24- or 60-GHz input, the measured input 1-dB compression points (P 1dB ) are 20.4 and 17.1 dBm at 24 and 60 GHz, respectively. For concurrent dual-tone 24- and 60-GHz input, the measured input P 1dB s are 17 and 14.5 dBm at 24 and 60 GHz, respectively. The measured input third-order intercept points are 29.4 and 26.8 dBm at 24 and 60 GHz, respectively. KEYWORDS BiCMOS, CMOS, dual-band switch, dual-band resonator, millimeter- wave, RFIC, SPDT switch 1 | INTRODUCTION Single-pole double-throw (SPDT) switches with low inser- tion loss (IL), high isolation, and large power-handling capa- bility are typically required for RF front-end subsystems. In multi-band systems, SPDT switches having multiband responses, especially with a multi-bandpass filtering func- tion, are desired for low cost, small size and convenient inte- gration. Several microwave and millimetre-wave SPDT switches have developed with single-wideband characteris- tics and utilized LC tuned, quarter-wavelength transmission line and matching network topologies. 1–3 Even though these switches have low IL, they do not show a multi-bandpass fil- tering function along with the switching function. This article presents a new concurrent dual-band SPDT switch realized in a 0.18-mm SiGe BiCMOS process that operates concur- rently in two different wide bands around 24 and 60 GHz. The SPDT switch is especially configured to operate as a dual-band resonator in the on-state operation for each output path and shows not only switching but also dual-bandpass filtering function. The concurrent dual-wideband switch pro- vides decent IL, good power handling, and compact size even though it operates with integrated band-pass filtering at both 24 and 60 GHz concurrently. 2 | SWITCH ARCHITECTURE, DESIGN, AND ANALYSIS Figure 1A shows the schematic of the concurrent dual- wideband SPDT switch. It is realized by two symmetric switching branches, each consisting of series (M 1 or M 3 ) and shunt (M 2 or M 4 ) transistors, shunt inductor L r , and shunt L 1 -C 1 or L 2 -C 2 . Body-floating technique is applied to all the nMOS transistors designed with deep n-well for enhanced isolation and reduced transistors’ parasitic capaci- tances. 4 L 1 -C 1 and L 2 -C 2 are combined into L n -C n connected in shunt at port 1 between the two switching branches, where C n 5 C 1 1 C 2 and L n 5 L 1 //L 2 , as shown in Figure 1B. UM AND NGUYEN | 1215