A Novel Tri-Band Wilkinson Power Divider for Multiband Wireless Applications

This letter presents a novel and simple technique for the design of an arbitrary tri-band Wilkinson power divider. The proposed technique is based on the use of quarter-wave open stubs (QWOS) at the desired operation frequencies, placed at appropriate positions along the divider's 50-Ω output transmission lines, to create the targeted tri-band response. These stubs present a high impedance at the frequencies of interest, while introducing transmission zeroes between the operation bands. For a compact design, slow-wave structure has been adopted to miniaturize the conventional divider's arms. To validate the above concept, a power divider-intended to operate in the 1.5-, 1.9-, and 2.35-GHz frequency bands-is designed. The results of the fabricated circuit present low insertion loss of less than 0.45 dB while offering an isolation better than 15 dB in the three bands of operation. Compared to recently published results, the proposed divider exhibits the largest fractional bandwidth at each operation frequency. Furthermore, it can be easily extended to more bands by adding QWOS depending on the required number of bands.