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ABSTRACT In this article, a compact diplexer is proposed using the U-shaped slotline resonator (U-SR) and dual-mode slotline resonator (DM-SR) for wideband and WLAN applications. The filter using the U-SR has three transmission poles in the passband and two transmission zeros near the passband edges. The wide upper-stopband can be realized for the second mode of the U-SR is well suppressed. The DM-SR has two resonant frequencies (odd- and even-modes) in the desired passband. And the odd-mode resonant frequency can be flexibly controlled by the slotline stub, whereas the even-mode one is fixed. Due to the main path signal counteraction and source-load coupling, the filter using the DM-SR possesses two transmission zeros in the upper-stopband. The mutual loading effect of two filters can generate new transmission zeros, which are mainly applied to improve the isolation. Compact size can be obtained without extra matching network. A diplexer prototype is designed, and good agreement can be obtained between measured and simulated results. © 2014 Wiley Periodicals, Inc. Microwave Opt Technol Lett 56:2480-2484, 2014 [ABSTRACT FROM AUTHOR]

ABSTRACT A small-size strip monopole antenna with dual feeds disposed at one corner of the supporting metal plate of the display of the tablet computer for LTE/WWAN operation is presented. The strip monopole is configured into a simple inverted-L shape of 29 mm (less than 0.08 wavelength at 750 MHz) and has a low profile of 10 mm above the two side edges of the corner. A first end of the strip monopole can be connected to a first ON/OFF switch (switch-1) for lower-band operation, while a second end of the strip monopole can be connected to a second ON/OFF switch (switch-2) for higher-band operation. When switch-1 is ON with switch-2 OFF, the antenna is fed at port-1. In this case, with the aid of a wideband matching circuit, the antenna can provide a wide lower band to cover the LTE band13 and GSM850/900 operation (746-960 MHz). When switch-1 is OFF with switch-2 ON, the antenna is fed at port-2 and can provide a wide higher band to cover the GSM1800/1900/UMTS/LTE2300/2500 operation (1710-2690 MHz). Good radiation characteristics for frequencies over the antenna's operating bands are also obtained. Operating principle of the antenna is described in the article. Experimental results and parametric studies of the antenna are presented. © 2013 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:2571-2576, 2013 [ABSTRACT FROM AUTHOR]