RF Bandpass Filter Emailksu chenyufugmail com UltraWideband UWB

RF Bandpass Filter 學生：陳昱夫 E-mail：ksu. chenyufu@gmail. com

Ultra-Wideband (UWB) Bandpass Filter With Embedded Band Notch Structures (1) Proposed UWB BPF with embedded band notch stubs. Predicted and the measured results for Filter-A with the FCC indoor mask.

Ultra-Wideband (UWB) Bandpass Filter With Embedded Band Notch Structures (2) Insertion loss of the embedded stub with varying gap for Ws =0. 1 mm and Wc = 1. 3 mm. Schematic diagrams of (a) conventional open-circuited stub, (b) spurline, and (c) proposed embedded open- Full-wave EM simulation of the complete layout of the designed circuited stub. UWB BPF with varying equal stub lengths.

Ultra-Wideband (UWB) Bandpass Filter With Embedded Band Notch Structures (3) • 製作於FR 4板、介電常數為 3. 05 基板高度 0. 508 損失 0. 025 • 不具有傳輸零點 • 具有一個可調式notched band • 結構尺寸 22. 2 mm X 15. 1 mm，大約為 1. 07λg X 0. 54λg。 • 中心頻率在 5. 83 GHz

Investigation in Open Circuited Metal Lines Embedded in Defected Ground Structure and Its Applications to UWB Filters (1) Schematic diagrams of (a) top view of proposed UWB BPF, (b) bottom view of proposed UWB BPF, (c) top view of proposed UWB BPF with notch band implementation, (d) bottom view of proposed UWB BPF with notch band implementation Simulated and measured results of Fabricated UWB BPF.

Investigation in Open Circuited Metal Lines Embedded in Defected Ground Structure and Its Applications to UWB Filters (2) • 製作於FR 4板、介電常數為 4. 4、基板高度 0. 8、損失為 0. 025。 • 具有兩個傳輸零點，分別在 1. 65 GHz和 11. 36 GHz。 • 具有一個notched band 。(只可控制頻寬) • 結構尺寸 11. 7 mm X 6. 3 mm、大約為 0. 41λg X 0. 22λg。 • 中心頻率為 5. 5 GHz

Ultra Wideband Bandpass Filter with Dual Notch Bands (1) Structure of the proposed UWB filter Simulated and measured frequency responses and (b) group delay of the fabricated UWB BPF. The dimensions are W 1 = 0. 1, W 2 = 0. 7, W 3 = W 5 = 1. 8, W 4 = 0. 7, Lc = 4, L 1 = 4. 4, L 2 = L 4 = 2, L 3 = 3. 3, L 5 = 4. 2, d = 4. 2, S 1 = 0. 1, S 2 = S 3 = 0. 2. All are in mm.

Ultra Wideband Bandpass Filter with Dual Notch Bands (2) (a) Structure of the square etched MMR and (b) |S 21|- magnitude of the MMR with different coupled line lengths (Lc). |S 21|-magnitude

Ultra Wideband Bandpass Filter with Dual Notch Bands (3) |S 21|-magnitude in comparison of SIR 1 SIR 2 with tuning 1.

Ultra Wideband Bandpass Filter with Dual Notch Bands (4) • 製作於Duroid 6010板、介電常數為 10. 2、 基板高度為 1. 27、損失 0. 0023。 • 整個通帶從 3. 1 GHz~11 GHz。 • 不具有傳輸零點。 • 具有兩個可調式notched band 。 • 結構尺寸為 13. 4 mm X 8. 62 mm。

Compact Ultra-Wideband Bandpass Filter Using Dual-Line Coupling Structure(1) Topology of the compact UWB BPF Simulated and measured results of the fabricated BPF with spurious response suppression.

Compact Ultra-Wideband Bandpass Filter Using Dual-Line Coupling Structure(3) l超寬帶帶通 4. 9和10. 9 GHz l返回損失超過 15 db從 5. 7至 10. 7 GHz l在 1分貝插入損耗約 5 GHz帶寬，最小 插入損耗為 0. 49 d. B的7. 3 GHz。 S-parameters and group delay of the UWB BPF.

A New Dual-Band Microstrip Bandpass Filter Using Net-Type Resonators

INTRODUCTION λ/2 SIRs shown in Fig. 1(a-1) and (a-2) are employed to design dual-band filters with two passbands at frequencies ƒ 1 and ƒ 2 (ƒ 2 > ƒ 1). The frequency ratio ƒ 2/ƒ 1 determines which type of SIRs ( K <1 or K>1 ) should be adopted.

INTRODUCTION λ/4 SIR shown in Fig. 1(b-1) was evolved into the net-type resonator [9] depicted in Fig. 1(c-1) and (d-1), and then exploited to design a single passband filter.

INTRODUCTION Fig. 2. Spurious resonant frequencies of the λ/4 stepped-impedance resonator With K=Z 2/Z 1 <1 and K=Z 2/Z 1 >1 the net-type resonator in the K>1 region shown in Fig. 2 is developed to achieve two closely specified resonant frequencies. The filter developed in this letter not only has two transmission zeros to improve the selectivity of each passband, but also provides a wide stopband suppression and an excellent mid-band rejection between two passbands.

DUAL-BAND NET-TYPE RESONATOR • To design the λ/4 SIR with two close resonant frequencies, ƒ 1 and ƒ 2 (ƒ 2/ƒ 1 ≈ 2). It is comprised of two transmission lines with the equal electrical length and the impedance ratio K=Z 2/Z 1 > 1. • The high impedance (Z 2) line is kept open-circuited while the low impedance (Z 1) line is connected to the ground. Hence, the first two resonant frequencies f 1 and f 2 (f 2 > f 1) of this λ/4 SIR

DUAL-BAND NET-TYPE RESONATOR Since the electrical lengths of two sections of the SIR are set to equal, the net-type resonator can be folded to a square box shape as shown in Fig. 1(d-2). The low impedance line can be equivalent to three parallelconnected stubs as shown in Fig. 1(c-2).

DUAL-BAND NET-TYPE RESONATOR Note that neither the value of K nor ƒ 2/ƒ 1 is restricted to an integer. Fig. 3 shows the resonant frequencies of the net-type resonators with K = 1. 57 (ƒ 2/ƒ 1 = 2. 5) and K = 3 (ƒ 2/ƒ 1 = 3) Fig. 3. Resonant frequencies of the nettype resonator with K = 1. 57 and 3.

DESIGN OF DUAL-BAND FILTER The resonators 1 and 4 are designed to simultaneously operate at the center frequencies ƒ 1 and ƒ 2 of he first and second passbands. The resonators 2 I and 3 I are designed to operate at ƒ 1 while the resonators 2 II and 3 II are designed to operate at ƒ 2 (a) Coupling structure

DESIGN OF DUAL-BAND FILTER The filter is fabricated on a RO 4003 substrate with a thickness of 0. 508 mm, a dielectric constant of 3. 38, and a loss tangent of 0. 0027. The center frequencies of two passbands are set To ƒ 1 =1 GHz and ƒ 2 =2 GHz schematic layout of the dual-band BPF using net-type resonators.

DESIGN OF DUAL-BAND FILTER • Substituting ƒ 1 and ƒ 2 into (1), one can obtain the impedance ratio K = 3 , and then calculate the electrical length Ɵ = 60 o (1) • using (2). Here Z 1 and Z 2 are chosen as 60Ω and 20Ω , respectively. (2) • The fractional bandwidths (FBWs) of first and second passbands are ∆1 = 4. 6% and ∆ 2 = 4. 8%

SIMULATED AND MEASURED RESULTS It occupies a circuit size of 41. 83 X 31. 73 mm 2. The simulated and measured results are illustrated in Fig. 5(b), and their enlarged views of the responses are given in Fig. 5(c). Circuit photograph of the developed filter. Simulated and measured results covering two passbands and their enlarged views of responses.

SIMULATED AND MEASURED RESULTS • the mid-band rejection between two passbands is greater than 40 d. B from 1. 14 GHz to 1. 75 GHz. • It is because the open stub in the resonator 1 or 4 individually gives a transmission zero at around 1. 5 GHz. • then the coupling between resonators 1 and 4 makes two transmission zeros split at 1. 33 and 1. 55 GHz.