Title :
Chip-type LTCC-MLC baluns using the stepped impedance method
Author :
Tang, Ching-Wen ; Sheen, Jyh-Wen ; Chang, Chi-Yang
Author_Institution :
Inst. of Electr. Commun. Eng., Nat. Chiao Tung Univ., Hsinchu, Taiwan
fDate :
12/1/2001 12:00:00 AM
Abstract :
A chip-type low-temperature co-fired ceramic (LTCC) multilayer ceramic (MLC) balun is presented in this paper. This balun is designed using the stepped impedance method. It uses a multilayer structure, meander lines, and multisection coupled lines. The use of multisection couple lines that have various characteristic impedance ratios can shrink the length of a quarter-wavelength coupled-transmission line and makes it very easy to match various impedances of balanced output. The proposed chip-type balun operates over a bandwidth of 2.25-2.65 GHz. The in-band phase and amplitude balances are excellent because of the symmetric structure and transmission-line trimming section. Measured results of the chip-type LTCC-MLC balun match well with the computer simulation
Keywords :
MMIC mixers; UHF mixers; baluns; coupled transmission lines; equivalent circuits; impedance matching; 2.25 to 2.65 GHz; 2.4 GHz; 50 ohm; ISM frequency band; balanced output; bluetooth RFIC; characteristic impedance ratios; chip-type LTCC-MLC balun; coupled transmission line; design equations; equivalent capacitance; equivalent circuit; impedance matching; in-band amplitude balances; in-band phase balances; meander lines; multisection coupled lines; quarter-wavelength coupled-transmission line; stepped impedance method; symmetric structure; transmission-line trimming section; Bandwidth; Ceramics; Coupling circuits; Distributed parameter circuits; Equivalent circuits; Impedance matching; Impedance measurement; Nonhomogeneous media; Transmission line theory; Transmission lines;
Journal_Title :
Microwave Theory and Techniques, IEEE Transactions on
