Balanced‐to‐unbalanced power dividers for arbitrary power division ratios and forarbitrary real termination impedances

Abstract

Novel balanced-to-unbalanced power divider (BUPD) is introduced for arbitrary power division ratios and for arbitrary real termination impedances. It consists of one 180° transmission-line section (TL), two different 90° TLs and one isolation circuit comprising two different resistances and two different 90° TLs. Due to the arbitrary termination impedances, the conventional ways for the even-and odd-mode excitation analyses are impossible, requiring a new design method. Under the assumption of the perfect isolation between two output ports, the BUPD can be divided into two, based on which the design formulas for the characteristic impedances of all the TLs can be successfully derived. Then, the scattering parameters are inversely derived, which is quite different from the conventional ways where the design formulas are derived based on the scattering parameters. For the verification of the suggested theory, one prototype for the power division ratio of 5 dB and for the termination impedances of 60, 40 and 50 Ω is tested. The measured frequency responses are in good agreement with the predicted ones.

Design of a compact microstrip balanced‐to‐balanced filtering power divider with real impedance‐transformation functionality

“…Then, if selecting k c = 0.37 and Z c = 75 Ω for the input coupled-line, the value of Figure 4b, the dimensions of the coupled three-line can be found. Finally, by analysing the theoretical response with Equations (15) and (16), all design parameters are obtained as shown in Table 2; the theoretical mixed-mode S-parameters of the three design examples are displayed in Figure 5a. Further, two design examples with impedance ratios of Z 02 : Z 01 = 1:1 and 2:1 (Z 01 = 50 Ω) shown in Figure 5a are modelled and simulated using full-wave simulation software AnsysEM 18.0 based on the initial sizes shown in Tables 1 and 2.…”

“…Then, the theoretical S-parameters of balun BPF considering the two loaded stubs are investigated as depicted in Figure 3b. Electrical length θ 3 is primarily determined by (15), and the value of θ 2 is obtained with (16). In Figure 3b, the navy lines with triangle symbols represent the initial results with θ 2 = 81.7°and θ 3 = 8.3°.…”

“…For increased signal immunity to environmental noise, electromagnetic interference and crosstalk in wireless communication systems, most passive circuits such as bandpass filters (BPFs) [1,2], diplexers [3,4], couplers [5,6] and power dividers (PDs) [7][8][9][10][11][12][13][14][15][16] are designed with balanced input/output ports. In some balanced radio frequency communication systems, the trans-receiver modules usually require some of these components to be cascaded together-for example, the balanced BPF and PD function in the feeding networks of differential antenna arrays and the signal transmission blocks between antennas and low-noise amplifiers [10].…”

Balanced‐to‐unbalanced and balanced‐to‐balanced filtering rat‐race couplers using multilayer substate integrated waveguide cavities

“…To build a high-performance balanced system, reported works regarding the balanced components are increasing, such as balanced filters [8,9], balanced power dividers [10][11][12] and balanced couplers [13,14]. For further high integration and multiple functions, work on balanced FRCs are emerging.…”