Miniaturization and harmonic suppression of branch-line and rat-race hybrid coupler using compensated spiral compact microstrip resonant cell

In this paper, a compensated spiral compact microstrip resonant cell (SCMRC) is applied to design a miniaturized microstrip rat-race and branch-line hybrid coupler. The proposed structures can achieve both a significant reduction of size and harmonic suppression. As the SCMRC are constructed entirely from microstrip lines, the couplers are easily fabricated using conventional printed-circuit board fabrication process. The proposed rat-race coupler occupies only 30% of conventional one's area, while the area of the branch-line coupler with the compensated SCMRC is 24% of the conventional case. On the other hand, the performance of the proposed couplers is as good as that of the corresponding conventional structures and deep harmonic suppression in addition. The design and simulation have been performed using full-wave analysis based on ADS Momentum

[1]  Masahiro Muraguchi,et al.  Reduced-size branch-line and rat-race hybrids for uniplanar MMIC's , 1990 .

[2]  Sang-Won Yun,et al.  Miniaturized 3-dB ring hybrid terminated by arbitrary impedances , 1994 .

[3]  Y. Yagi,et al.  Miniaturized 90 degree hybrid coupler using high dielectric substrate for QPSK modulator , 1996, 1996 IEEE MTT-S International Microwave Symposium Digest.

[4]  Tatsuo Itoh,et al.  A uniplanar compact photonic-bandgap (UC-PBG) structure and its applications for microwave circuit , 1999 .

[5]  Quan Xue,et al.  Novel 1-D microstrip PBG cells , 2000 .

[6]  Quan Xue,et al.  A novel microstrip ring hybrid incorporating a PBG cell , 2001 .

[7]  Quan Xue,et al.  A novel microstrip ring hybrid incorporating a PBG cell , 2001, IEEE Microwave and Wireless Components Letters.

[8]  Kimberley W. Eccleston,et al.  Compact planar microstripline branch-line and rat-race couplers , 2003 .

[9]  Quan Xue,et al.  Novel subharmonically pumped mixer incorporating dual-band stub and in-line SCMRC , 2003 .

[10]  Shih-Ming Wang,et al.  A study of meandered microstrip coupler with high directivity , 2003, IEEE MTT-S International Microwave Symposium Digest, 2003.

[11]  Y. Kim,et al.  Size reduction and harmonic suppression of rat-race hybrid coupler using defected ground structure , 2004, IEEE Microwave and Wireless Components Letters.

[12]  H. Ghali,et al.  Miniaturized fractal rat-race, branch-line, and coupled-line hybrids , 2004, IEEE Transactions on Microwave Theory and Techniques.