Design and study of improved Miniature and Dual-Band 180˚ Hybrid Coupler with Harmonic-Suppression
| Autor: | CHENG, MING-JEN, 鄭明仁 |
|---|---|
| Rok vydání: | 2017 |
| Druh dokumentu: | 學位論文 ; thesis |
| Popis: | 105 This work is designed and improved for 180° hybrid coupler, making it to be a circuit with miniaturization, harmonic suppression and dual frequency operation. The stepped impedance unit module is implemented by a complementary-conducting-strip (CCS) transmission line. The unit module is used as a base to replace the 1/4-λg of total length 6/4-λg transmission line, the appropriate proportion of the design to make the circuit miniaturization and dual-band operation, coupled with two-layers open stub to suppress the harmonic. The CCS TL is used to replace the conventional microstrip line to form the stepped impedance line and the open stub by extracting the CCS TL electrical parameters under different specifications, and this unit module is used to replace the microstrip 1/4-λg transmission line of the ring-shaped 180° hybrid. The six unit modules are connected in cascade to form a full-length 6/4-λg miniaturized, dual-band (2.45/5.8-GHz) 180° hybrid with harmonic suppression. The results show that the proposed circuit occupied area (excluding I / O PADs) (= 1.5√3 a2, a = 7.3 mm) is only 138.41 mm2. The occupied area of proposed circuit to the traditional ring-shaped rat-race (excluding I/O PADs) (= π × b2, the radius b is 18.44 mm) is only 13%, and the area reduction factor(ARF) is up to 87 %. The optimum frequency is shifted about 0.1 GHz from f1/f2 (2.45/5.8-GHz) to f1'/f2'(2.55/5.9-GHz) by the measurement results of the prototype circuit of the 180 ° hybrid. Through the implementation shows that the circuit has dual-band operation (f1'/f2', 2.55/5.9-GHz) and harmonic suppression characteristics. For the electrical characteristics of the dual-band operation, the electrical response of the Σ port is 20.6 dB for the input return loss (|S11|) at the operating frequency of f1'(2.55 GHz), and the insertion loss (|S21|/|S31|)is 3.4 dB and 3.6 dB, the phase difference (S21-S31) is -5.3 degrees, and the isolation (|S41|) is 23.8 dB, at 20-dB return loss, 20-dB isolation of the fractional bandwidth (FBW) is 19.8% (2.39–2.9 GHz), the amplitude imbalance is less than 0.7 dB, the phase difference is less than 9 degrees; the other operating frequency at f2'(5.9 GHz), the input return loss (|S11|) is 12.2 dB, the insertion loss (|S21|/|S31|) is 5.5 dB and 5.8 dB, the phase difference (S21-S31) is -1.6 degrees, and the isolation (|S41|) is 19.4 dB. At 10-dB return loss, 10-dB isolation of the FBW is 4.2% (5.87–6.12 GHz), where the amplitude imbalance is less than 1 dB (5.87–5.97 GHz) and the phase difference is less than 10 degrees (5.87–6.08 GHz).The electrical response of the Δ port is 22.8 dB for the input return loss (|S44|) at the operating frequency of f1'(2.55 GHz), the insertion loss (|S24|/|S34|) is 3.4 dB and 3.7 dB, the phase difference is 7.3 degrees, the isolation (|S14|) is 19.4 dB, and the FBW at 20-dB return loss, 20-dB isolation is 18.0% (2.49 GHz-2.95 GHz), the amplitude imbalance is less than 0.6 dB, the phase difference is less than 10 degrees； the input return loss (|S44|) at the operating frequency of f2'(5.9 GHz) is 22.9 dB, the insertion loss (|S24|/|S34|) is 7.1 dB and 6.5 dB, respectively, the phase difference (S24-S34-180°) is 1.9 degrees, and the isolation (|S14|) is 19.4 dB. At 10-dB return loss, 10-dB isolation of the FBW is 2.4% (5.84–6.08 GHz), where the amplitude imbalance is less than 1 dB (5.84–6.05 GHz) and the phase difference is less than 10 degrees (5.86–5.93 GHz). In addition, the electrical response of the harmonic suppression, the electrical response of the Σ port (|S21|/|S31|) and the Δ port (|S24|/|S34|) at the harmonic frequency of 5.1 GHz (2f1'), 7.65 GHz (3f1'), 10.2 GHz (4f1'), 11.8 GHz (2f2') and 12.75 GHz (5f1'), respectively, with the ability of 56.8 dB, 37.6 dB, 18.1 dB, 43.1 dB and 45.2 dB, the harmonic suppression level is at least 18 dB in the range of 2f1'-5f1'(including 2f2'). |
| Databáze: | Networked Digital Library of Theses & Dissertations |
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