Double-sided Parallel-strip Line Research Articles

Pattern Switchable Antenna System Using Inkjet-Printed Directional Bow-Tie for Bi-Direction Sensing Applications.

In this paper, we propose a paper-based pattern switchable antenna system using inkjet-printing technology for bi-direction sensor applications. The proposed antenna system is composed of two directional bow-tie antennas and a switching network. The switching network consists of a single-pole-double-throw (SPDT) switch and a balun element. A double-sided parallel-strip line (DSPSL) is employed to convert the unbalanced microstrip mode to the balanced strip mode. Two directional bow-tie antennas have different radiation patterns because of the different orientation of the reflectors and antennas. It is demonstrated from electromagnetic (EM) simulation and measurement that the radiation patterns of the proposed antenna are successfully switched by the SPDT switch.

Wideband Balanced Network with High Isolation Using Double-Sided Parallel-Strip Line

A new wideband balanced power dividing/combining network with high isolation is proposed in this paper. The differential/common mode equivalent circuits of the balanced network can be easily reduced based on the matrix transformation. Two double-sided parallel-strip line (DSPSL) 180 $^{\circ}$ phase inverters loaded with four isolation resistors are used to realize high isolation for the power division output ports. A planar wideband balanced network with bandwidth 52.7% of (1.68–2.84 GHz, $\vert S_{{\rm dd}21}, S_{{\rm dd}31}\vert >- 4$ dB) for the differential mode and high isolation for the differential/common mode is designed and fabricated. The measured results show good agreement with the theoretical expectations.

Dual-Band Out-of-Phase Power Divider With Impedance Transformation and Wide Frequency Ratio

A novel dual-band out-of-phase power divider (PD) with impedance transformation and wide frequency ratio is proposed in this letter. This proposed circuit consists of four double-sided parallel-strip lines (DSPSLs) to obtain the out-of-phase and dual-band performance, mid-inserted conductor plane as a common ground, and two resistors to improve the output port isolation. A through ground via (TGV) is employed to realize the high power application. By using rigorous even- and odd-mode analysis, a set of closed-form equations and design procedures are obtained and the analysis indicates that this PD can operate at two arbitrary frequencies with wide frequency ratio $(2.44\leq k \leq 7.31)$ . Furthermore, an experimental circuit is designed, and fabricated. The simulated and measured results agree very well to verify our design theory.

잉크젯 프린팅 기술을 이용한 종이 기반의 방사패턴 가변 안테나

본 논문에서는 잉크젯 프린팅 기술을 이용한 새로운 종이 기반의 방사패턴 가변 안테나를 제안한다. 제안된 안테나는 2개의 bow-tie 안테나와 스위칭 네트워크로 구성되어 있다. 2개의 bow-tie 안테나는 종이의 앞면과 뒷면에 일반 가정용 잉크젯 프린터로 인쇄되었고, 스위칭 네트워크는 PCB 기판에 SPDT와 발룬으로 제작하였다. 복잡한 신호 인가와 발룬소자의 사용 대신 두 개의 마이크로스트립 선로를 평행하게 위치시킴으로 불 평형 신호를 평형 신호로 바꿔주는 발룬의 역할을 대신하였다. 2개의 bow-tie 안테나에 다른 방향으로 반사체를 추가함으로써 각각의 방사패턴을 서로 다르게 하였다. 제안된 가변형 안테나는 EM 시뮬레이션과 측정 결과를 통해 성공적으로 방사패턴이 가변됨을 확인할 수 있다.

COMPLEX IMPEDANCE-TRANSFORMATION OUT-OF-PHASE POWER DIVIDER WITH HIGH POWER-HANDLING CAPABILITY

A novel 180 ◦ out-of-phase power divider with complex-source to complex-load impedance transformation and high power-handling capability is proposed in this paper. It is composed of three double-sided parallel-strip lines (DSPSLs), a conduct plane in the middle as common ground, and two resistors for heat sinking and high isolation. Based on the rigorous odd- and even-mode analytical methods, closed-form design equations about electrical parameters are obtained. To demonstrate our design theory, a practical three-layer out-of-phase power divider is designed, simulated and measured. The measured results show that the return losses |Sii| (i = 1, 2, and 3) are all larger than 17 dB. The insertion loss |S21|(|S31|) is 3.6 dB (3.7 dB). The isolation |S23| is �24 dB, and the output phase difference is �177 ◦ at the operating frequency. Good agreements between the simulated and measured results verify our design theory.

A Compact Differential Filtering Quasi-Yagi Antenna With High Frequency Selectivity and Low Cross-Polarization Levels

A compact differential filtering quasi-Yagi antenna is proposed for high frequency selectivity and low cross-polarization. The proposed antenna is formed by inserting a double-sided parallel-strip line (DSPSL) filter between the driver and the reflector of the quasi-Yagi antenna. This integration enables the antenna to achieve both high frequency selectivity and compact size. An antenna prototype exhibits a 10-dB return loss bandwidth of 1.77-1.87 GHz, peak gain of 5.6 dBi, and maximum cross-polarization levels of -22/-17 dB in E-/H-planes at 1.81 GHz. The out-of-band suppression is enhanced by 14.4 and 11.8 dB at 1.67 and 1.97 GHz compared to the quasi-Yagi antenna itself, respectively.

Novel Broadband Center-Fed UHF Near-Field RFID Reader Antenna

A broadband center-fed ultra-high frequency (UHF) near-field radio frequency identification (RFID) reader antenna is proposed and investigated in this letter. The design utilizes four tapered double-side parallel stripline (TDSPSL)-fed dipoles to form a circular loop to achieve broadband impedance matching and strong and uniform magnetic field distribution. Parametric studies are carried out to characterize the design concept. The proposed antenna was fabricated and measured. The measured 10-dB impedance bandwidth is 236 MHz (814-1050 MHz), which covers the entire UHF RFID frequency band. The maximum reading distance is 210 mm at 30 dBm input power. Moreover the antenna can achieve a 100% read percentage within the height of 135 mm for multitag detection. The measured results agree well with the simulated ones.

Wideband balanced out‐of‐phase network based on double‐sided parallel‐strip line

A new wideband out-of-phase balanced power dividing/combining network is proposed in this study. Large bandwidth for the differential mode with broadband common mode suppression can be easily realised. Out-of-phase power division can be also achieved for Ports 2, 3 (Port 2′, 3′) by the double-sided parallel-strip line 180° swap. A planar wideband balanced out-of-phase network with bandwidth of 33% for the differential mode with wideband common mode suppression is designed and fabricated for demonstration. Good agreement is observed between simulated and measured performances, indicating the validity of the proposed design strategies.

Impedance-Transforming Dual-Band Out-of-Phase Power Divider

An arbitrary impedance-transforming dual-band out-of-phase power divider using double-sided parallel-strip line (DSPSL) with inserted conductor plane is proposed. This out-of-phase power divider is mainly composed of two two-section dual-band impedance transformers, a conductor plane transforming DSPSL into microstrip lines, and four resistors. Odd and even-mode analyses show that the proposed power divider is able to operate at two frequencies of f1 and f2 with a wide frequency ratio range at . The proposed power divider has been demonstrated and verified. The experimental results show that the proposed out-of-phase power divider can realize the impedance transformation from Z0 to ZL with good return losses, fine isolation, low insertion losses and high stability of 180 ° phase difference.

Electrically Large Zero-Phase-Shift Line Grid-Array UHF Near-Field RFID Reader Antenna

A grid-array antenna using a zero-phase-shift (ZPS) line is proposed to enlarge the interrogation zone of a reader antenna for near-field ultra-high-frequency (UHF) radio frequency identification (RFID) system. The proposed grid-array antenna is composed of a number of grid cells and a double-sided parallel-strip line feeding network. Each grid cell, namely segmented loop constructed by the ZPS line, has uniform and single-direction flowing current along the line. By configuration of the cells sharing a common side with its adjacent grid cells which carry reverse-direction flowing current, a grid-array antenna is formed to generate a strong and uniform magnetic-field distribution over a large interrogation zone even when the perimeter of the interrogation zone reaches up to 3λ (where λ is the operating wavelength in free space) or larger. As an example, a grid-array antenna with 1 × 2 segmented ZPS line loop cells implemented onto a piece of FR4 printed board (PCB) is designed and prototyped. The results show that the grid-array antenna achieves the impedance matching over the frequency range from 790 to 1040 MHz and produces strong and uniform magnetic-field distribution over an interrogation zone of 308 mm × 150 mm.

A Novel Unequal Broadband Out-of-Phase Power Divider Using DSPSLs

In this paper, a novel unequal broadband out-of-phase power divider (PD) is presented. Double-sided parallel-strip lines (DSPSLs) are employed to achieve an out-of-phase response. Also, an asymmetric dual-band matching structure with two external isolation resistors is utilized to obtain arbitrary unequal power division, in which the resistors are directly grounded for heat sinking. A through ground via (TGV), connecting the top and bottom sides of the DSPSLs, is used to short the isolation components. Additionally, this property can efficiently improve the broadband matching and isolation bandwidths. To investigate the proposed divider in detail, a set of design equations are derived based on the circuit theory and transmission line theory. The theoretical analysis shows that broadband responses can be obtained as proper frequency ratios are adopted. To verify the proposed concept, a sample divider with a power division of 2:1 is demonstrated. The measured results exhibit a broad bandwidth from 1.19 GHz to 2.19 GHz (59.2%) with a return loss better than 10 dB and port isolation of 18 dB.

A Novel Unequal Broadband Out-of-Phase Power Divider Using DSPSLs

In this paper, a novel unequal broadband out-of-phase power divider (PD) is presented. Double-sided parallel-strip lines (DSPSLs) are employed to achieve an out-of-phase response. Also, an asymmetric dual-band matching structure with two external isolation resistors is utilized to obtain arbitrary unequal power division, in which the resistors are directly grounded for heat sinking. A through ground via (TGV), connecting the top and bottom sides of the DSPSLs, is used to short the isolation components. Additionally, this property can efficiently improve the broadband matching and isolation bandwidths. To investigate the proposed divider in detail, a set of design equations are derived based on the circuit theory and transmission line theory. The theoretical analysis shows that broadband responses can be obtained as proper frequency ratios are adopted. To verify the proposed concept, a sample divider with a power division of 2:1 is demonstrated. The measured results exhibit a broad bandwidth from 1.19 GHz to 2.19 GHz (59.2%) with a return loss better than 10 dB and port isolation of 18 dB.

Novel UHF Near-Field RFID Reader Antenna Based on Double-Sided Parallel-Strip Line

A novel reader antenna based on double-side parallel-strip line (DSPSL) for ultra-high frequency (UHF) near-field radio frequency identification (RFID) systems is proposed. The antenna is composed of a phase inverter, DSPSL structures, and four dipoles. The fabricated antenna works from 887 to 938 MHz with reflection coefficient less than -10 dB. The maximum reading distances are 200 and 70 mm when the input power is 30 and 17 dBm, respectively. Measurement results show that the antenna has good performance in near-field UHF RFID systems.

Three-Dimensional Dual-Polarized Frequency Selective Structure With Wide Out-of-Band Rejection

A new three-dimensional bandpass frequency-selective structure (FSS) is proposed for dual-polarized applications. Each square unit cell of the proposed FSS consists of vertical and horizontal double-sided parallel-strip lines (DSPSLs) and a thin metallic plate. Furthermore, the parallel-strip lines of every DSPSL are connected together through via holes. Using this arrangement, multimode resonators are established in the proposed structure. At lower frequencies, the substrate mode propagates and two resonators along the DSPSL are constructed, leading to a bandpass response with two transmission poles. At higher frequencies, the air mode is reflected by two resonates along the inserted plate, resulting in a stopband with two transmission zeros. The operating principle for this FSS is explained with the aid of an equivalent circuit model. Moreover, a parametric study of the proposed FSS is also carried out and design guidelines are formulated. As an example, a prototype of the proposed FSS is designed, fabricated, and tested. Measured results demonstrate that the FSS exhibits dual polarizations, high out-of-band rejection, and stable frequency response under both transverse electric (TE) and transverse magnetic (TM) polarizations of an obliquely incident wave.

MINIATURE FOLDED PRINTED QUADRIFILAR HELICAL ANTENNA WITH INTEGRATED COMPACT FEEDING NETWORK

A miniature folded printed quadrifllar helical antenna (FPQHA) using a novel compact feeding network is proposed. Folding and meandering techniques are used to obtain 66% of size reduction for the axial length of the printed quadrifllar helical antenna. A compact feeding network using an out-of-phase power divider based on double-sided parallel-strip lines and a Wilkinson power divider is designed. A fabricated prototype of the FPQHA employing the compact feeding network is presented. The measured positive gain bandwidth is from 380MHz to 425MHz with a re∞ection coe-cient less than i20dB and an axial ratio below 2dB. The measured maximum gain is 3.08dBic at 395MHz with a half-power beamwidth of 150 - . With good radiation performance and integrated feeding network, the proposed antenna can become a better candidate in satellite and mobile communications.

Design of a wideband bandpass filter based on signal-interaction concepts

A novel wideband bandpass filter (BPF) based on signal-interaction concepts is presented in this paper. Two transmission paths with a wideband double-sided parallel-strip line 180° inverter and a 3λ/4 transmission line are employed to transmit signals from Port 1 to Port 2. By introducing two λ/4 shorted lines, the passband transmission performance of the BPF can be improved effectively. The experimental results demonstrate that the proposed BPF can achieve three transmission zeros and good harmonic suppression in the whole operating band ranging from 1.35 to 3.41 GHz, with 3-dB fractional bandwidth of 86%.

REALIZATION OF MICROSTRIP BANDPASS FILTER BALUN USING DOUBLE-SIDED PARALLEL-STRIP LINE WITH NOVEL COUPLING SCHEME

In this paper, we propose a microstrip fllter balun adopting double-sided parallel-strip line (DSPSL) with a conductor plane inserted in the middle of the substrate. Fed by the DSPSL at input port, two microstrip fllters on top and bottom layers are excited simultaneously, with the frequency-independent out-of-phase feature obtained between two output ports. The proposed fllter balun exhibits excellent performance with good frequency selectivity because of multiple transmission zeros generated by a new coupling scheme. Finally, a fllter balun sample is designed and fabricated, and good agreement is obtained between its measured and simulated S- parameters.

Design of an Ultra-Wideband Transition from Double-Sided Parallel Stripline to Coplanar Waveguide

A design method of an ultra-wideband transition from double-sided parallel stripline (DSPSL) to coplanar waveguide (CPW) is proposed based on analytical expressions of characteristic impedance. The conformal mapping is used to obtain the characteristic impedance for each section of the transition within 3.7% accuracy as compared with the EM simulation results. An efficient and clear guideline for the design of the transition is proposed. The implemented transition performs less than 0.6 dB insertion loss per transition for frequencies from 40 MHz to 12 GHz and less than 1.2 dB insertion loss to 27 GHz, which well exceeds the previous results in the literature.

Electric Split-Ring Resonator Based on Double-Sided Parallel-Strip Line

A new electric split-ring resonator (ESRR) specialized for the double-sided parallel-strip line (DSPSL) is proposed. Adding a DSPSL swap to a split-ring resonator (SRR), its magnetic response becomes electrical, which is explained by even- and odd-mode analysis and resonant current distribution. Loading in a line with a series gap, it behaves similarly to the previously well-studied complementary SRR. ESRR may be useful in the design of novel DSPSL-based antennas and microwave components.

A BROADBAND OUT-OF-PHASE POWER DIVIDER FOR HIGH POWER APPLICATIONS USING THROUGH GROUND VIA (TGV)

In this paper, we present a broadband out-of-phase power divider with high power-handling capability. The proposed device consists of several sections of double-sided parallel-strip lines (DSPSLs), a mid-inserted conductor plane, and two external isolation resistors, which are directly grounded for heat sinking. A through ground via (TGV), connecting the top and bottom sides of DSPSLs, is employed. The special metal via is realized to short the isolation resistors at full-frequency band when the odd-mode is excited. Meanwhile, it can be ignored as the excitation is even-mode. This property is e-ciently utilized to improve the bandwidth. To examine the proposed power divider in detail, a set of closed-form equations are derived. Meanwhile, the power operation analysis illustrates that the proposed power divider is a good candidate for high power applications. The design charts show that the proposed device can support a wide frequency ratio range (1{1.7). Furthermore, broadband responses can be obtained when proper frequency ratios are adopted. For veriflcation, an experimental power divider operating at 1.25/1.75GHz is implemented. The measured results exhibit a bandwidth of 44.3% with better than 15dB return loss and 18dB port isolation is achieved.