A Dual-Band Balun Using Partially Coupled Stepped-Impedance Coupled-Line Resonators

In this paper, a recently proposed dual-band resonator structure consisting of a pair of partially coupled stepped-impedance lines is theoretically investigated. The new resonator configuration contains a number of attractive features for dual-band applications. A new type of dual-band balun that is constructed using a pair of such coupled stepped-impedance resonators is fully studied both theoretically and experimentally. Design equations for the balun are derived by an even- and odd-mode approach. A prototype of such dual-band balun operating at 900 MHz and 1.8 GHz is designed, fabricated, and measured. Good agreement between the designed and measured responses proves the concept of the dual-band balun and validates the design formulas.

[1]  K. Chen,et al.  Miniaturized coplanar waveguide bandpass filters using multisection stepped-impedance resonators , 2006, IEEE Transactions on Microwave Theory and Techniques.

[2]  R. Kaul,et al.  Microwave engineering , 1989, IEEE Potentials.

[3]  R. Engels,et al.  Improved compaction of multilayer MMIC/MCM baluns using lumped element compensation , 1997, 1997 IEEE MTT-S International Microwave Symposium Digest.

[4]  Zhang Yue Ping,et al.  A dual-band BPF for concurrent dual-band wireless transceiver , 2003, Proceedings of the 5th Electronics Packaging Technology Conference (EPTC 2003).

[5]  Hyo-Jong Lee,et al.  Design method of a dual band balun and divider , 2002, 2002 IEEE MTT-S International Microwave Symposium Digest (Cat. No.02CH37278).

[6]  Kenjiro Nishikawa,et al.  Compact and broad-band three-dimensional MMIC balun , 1999 .

[7]  Mitsuo Makimoto,et al.  Basic Structure and Characteristics of SIR , 2001 .

[8]  Pertti Vainikainen,et al.  Dual-frequency balun to decrease influence of RF feed cables in small antenna measurements , 2000 .

[9]  I. Pele,et al.  Dual-band power divider based on semiloop stepped-impedance resonators , 2003 .

[10]  Sheng-Fuh Chang,et al.  Dual-band step-impedance bandpass filter for multimode wireless LANs , 2004 .

[11]  Yue Ping Zhang,et al.  Dual-Band Microstrip Bandpass Filter Using Stepped-Impedance Resonators With New Coupling Schemes , 2006, IEEE Transactions on Microwave Theory and Techniques.

[12]  H. Knapp,et al.  Lumped and distributed lattice-type LC-baluns , 2002, 2002 IEEE MTT-S International Microwave Symposium Digest (Cat. No.02CH37278).

[13]  N. Marchand,et al.  Transmission-line Conversion Transformers , 1944 .

[14]  Ke-Li Wu,et al.  A Dual-Band Coupled-Line Balun Filter , 2007, IEEE Transactions on Microwave Theory and Techniques.

[15]  Kian Sen Ang,et al.  Analysis and design of miniaturized lumped-distributed impedance-transforming baluns , 2003 .

[16]  Chi-Yang Chang,et al.  Chip-type LTCC-MLC baluns using the stepped impedance method , 2001 .

[17]  G. R. Branner,et al.  A miniaturized lumped-distributed balun for modern wireless communication systems , 1996, Proceedings of the 39th Midwest Symposium on Circuits and Systems.