Analysis and design of compact two-way Wilkinson power dividers using coupled lines

Abstract

transformers are used in both designs, which provide even mode impedances of 70.7 X with a line spacing of 0.56 mm [8]. The area of the folded layout is 30% less than the unfolded layout. The simulated and the measured results are compared in Figures 8-10.In Figure 8, the insertion loss for both designs is shown. Because the layouts are symmetrical, only |S 21 | is compared with the simulation. It is found that the measured data fits the simulations well. The insertion loss at the center frequency is 3.2 and 15 dB at 1 and 4 GHz. The one section filter response is clearly observed. The measured 3-dB bandwidth is 60%, which fits the prediction of Figure 6. The return losses for input and output ports are shown in Figure 9. The measured 10-dB input return loss bandwidths are around 33%. The isolation between the two output ports is shown in Figure 10. CONCLUSIONA one section filter is integrated into the PD. The concept can be realized using open-ended coupled lines and shorted-end coupled. The relations between even mode and odd mode impedance are shown. However, fabrication limits restrict the practical implementation. Therefore, an alternative loaded line circuit without coupled lines is used, which provides more flexibility in choosing the bandwidth. Two designs with a center frequency of 2.4 GHz are fabricated and measured to validate the concept. A 3-dB insertion loss bandwidth of 60% and a 10-dB return loss bandwidth of 33% are measured. ABSTRACT: This paper describes a new low-profile X antenna array separated 0.1-0.15 wavelengths from a flat or rimmed square reflector of 0.6 wavelengths in size. The array consists of two closely spaced elements: an active two-port folded-wire X antenna, which radiates two cross-polarized fields and a passive X element. This very compact double X reflector antenna has around 8-9 dBi peak directive gain, 12.5% bandwidth on average around the design frequency of 1800 MHz, a high interport isolation (about 25-30 dB) and low cross-polarization in the whole input-match frequency range. The practical applications of the properly designed and tuned double X reflector antenna may include among others, base station antennas with polarization diversity for GSM PCS or DCS bands, or for the whole UMTS band.

Accurate Schiffman-type section design approach for microstrip line Wilkinson power divider

“…Mathematical calculation and selected examples are proved that: by suitable adjusting even-and odd-mode characteristic impedances and their electrical lengths, perfect matching of proposed WPD can be realized without any extra compensation structure. Although bandwidths of proposed WPD become a little narrow as coupling strengths increased, compared with previous work in [7], the bandwidths didn't decrease rapidly in the realizable design range of 1 < < 3.…”

“…Until now, S-Type section without any extra compensation structure has not been discussed in microstrip line structure. Theoretically, coupled line section WPDs [7,8] could be only designed in stripline structure, where the electrical lengths between even-and odd-mode are defined equally. Under the condition of microstrip line structure, extra lumped elements and extra coupled line section are compensated the characteristic impedance and phase difference [9,10,11].…”

An Unequal Coupled-Line Wilkinson Power Divider for Arbitrary Terminated Impedances

“…In recent years, many efforts have been made to develop high-performance power dividers [2][3][4][5][6][7]. After decreasing the inherent circuit size of the conventional Wilkinson power divider, a coupled-line section is used to design compact power divider in [8]. From the analyzed results of [8], it can be found that the odd-mode impedance of the coupled line is a free design variable.…”

“…After decreasing the inherent circuit size of the conventional Wilkinson power divider, a coupled-line section is used to design compact power divider in [8]. From the analyzed results of [8], it can be found that the odd-mode impedance of the coupled line is a free design variable. Therefore, the design tradeoffs among the output-ports matching, isolation and the odd-mode impedance can be easily achieved.…”

“…This kind of power divider consists of n lossless asymmetrical coupled-line sections. In fact, the proposed theory in [9] includes the design approach in [8] conceptually. In addition, three-port 3-dB Wilkinson power dividers terminated in arbitrary impedances are described in [10].…”