New UWB 1:2 Power Divider with Flat In-Band Splitting and Bandpass Filtering Functions

Abstract

This paper introduces a new U.S. ultra-wideband(UWB: 3.1~10.6 GHz) 1:2 power divider based on a single section Wilkinson type configuration. The divider provides very flat in-band power splitting, high isolation, low insertion loss, sharp roll-off bandpass filtering, and DC blocking characteristics. The circuit consists of a <TEX>$\lambda$</TEX>/4 Y resonator, three capacitively coupled <TEX>$\lambda$</TEX>/2 short-circuited lines, and a resistor between the two output ports. The circuit structure was simulated with ADS and HFSS, and realized with low-temperature co-fired ceramic(LTCC) green tape, which has a dielectric constant of 7.8. <TEX>$|S_{11}|$</TEX> better than 10 dB, <TEX>$|S_{21}|$</TEX> and <TEX>$|S_{31}|$</TEX> less than 3.2 dB, with both <TEX>$|S_{22}|$</TEX> and <TEX>$|S_{32}|$</TEX> measured as better than 12 dB for the whole UWB band. Measurement results agree closely with HFSS simulation results. The power divider has a compact size of <TEX>$4\times9\times0.6mm^3$</TEX>.