Double-sided Parallel-strip Line Research Articles

WIDEBAND PLANAR WILKINSON POWER DIVIDER USING DOUBLE-SIDED PARALLEL-STRIP LINE TECHNIQUE

A new design of a wideband Wilkinson power divider using double-sided parallel strip line technique is presented in this paper. To obtain a good isolation value, the proposed design was integrated with three isolation resistors. The proposed power divider is designed for a wide range of frequencies between 2 GHz to 6 GHz with all the ports matched to 50Ω. The conventional quarter wavelength arms are divided into three different widths to ensure wideband capabilities. Moreover, the novelty of the proposed design is illustrated from the double-sided parallel-strip line technique where proposed design is using similar structure at both the top and bottom layers to ensure balance of transmission. All dimensions for the transmission line section were optimized to achieve wideband operation and were integrated with a lumped element. This design can be used as a doublesided feeder for a microstrip antenna.

Miniaturization of Rat-Race Coupler With Dual-Band Arbitrary Power Divisions Based on Stepped-Impedance Double-Sided Parallel-Strip Line

Generalized equations are presented for the design of a rat-race coupler with a phase inverter and an arbitrary power division, where its four arms are built by symmetric reciprocal lossless two-port networks. According to these equations, uniform- and stepped-impedance rat-race couplers are analyzed and synthesized with dual-band arbitrary power divisions. The relationships between the geometries and the design specifications of proposed dual-band rat-race couplers are completely determined. Under such circumstances, the most compact configuration of the stepped-impedance rat-race coupler is achieved when the maximum allowable impedance ratio is applied for all its arms. Several prototypes are realized with double-sided parallel-strip lines (DSPSLs) and DSPSL phase inverters. As the stepped-impedance arms are not limited to simulate 90° sections and the phase inverters are implemented into our proposed dual-band couplers, the component circumferences are reduced significantly by 65%-70%, in comparison with their conventional 540° counterpart. Their good performances are demonstrated by the simulated and measured results.

Novel Dual-Band Out-of-Phase Power Divider With High Power-Handling Capability

In this paper, we present a novel dual-band out-of- phase power divider with high power-handling capability. The proposed device consists of five ports including one input port, two output ports, and two extra ones, which are connected by the external isolation resistors. To obtain the out-of-phase feature between the two output ports, double-sided parallel-strip lines are employed, and a conductor plane is inserted in the middle of the substrate as a common ground. A set of closed-form design equations is developed for analysis of the novel design structure by using the rigorous even- and odd-mode analysis method. The analysis shows that the proposed power divider can operate at two frequencies of f1 and mf1 with a wide frequency ratio range at 1.62 <; m <; 3. Furthermore, the power operation analysis also illustrates that the new circuit is superior in high power-handling capability over the conventional dividers with internal isolation resistors. For verification, an example power divider with frequency ratios of 2.4:1 is implemented. Simulation and experimental results agree well, validating the proposed design methodology.

A Dual Frequency Microstrip Antenna Using a Double Sided Parallel Strip Line Periodic Structure

A dual-frequency microstrip antenna is presented. The proposed antenna consists of a rectangular radiating patch, the ground, and a periodic offset double-sided parallel-strip line structure that is used as the substrate. The phase constant of the substrate is less than 0 at the frequency of operation, which makes the rectangular microstrip antenna work in different modes, and has two resonant frequencies. Experimental results show that the proposed antenna works at 3.3 GHz and 3.9 GHz.

Neural Network Method for Dual-Mode Dual-Band DSPSL Bandpass Filter Design

A dual-mode dual-band bandpass filter using double-sided parallel-strip lines (DSPSL) is proposed in this article. This design is based on vertical coupling, which doesn’t require any via holes. A method based on neural-network is developed and applied to analyze the DSPSL filter design. Through the neural network analysis of nonlinear circuits, it can enhance the efficiency of electro-magnetic (EM) analysis techniques for DSPSL filter design. A multilayer perception neural network (MLPNN) is implemented to model the microwave DSPSL filter circuit. Quasi-Newton method is adopted, which has shorter training period and the faster convergence. The trained artificial neural network (ANN) model maps a set of scatting parameters for the DSPSL filter in terms of its geometric parameters. A good agreement between ANN results and EM simulations verifies the validity of this proposed MLPNN model.

Dual‐band branch‐line coupler using double‐sided parallel‐strip line

AbstractIn this article, a three branch‐line coupler is proposed for the dual‐band application. The coupler can operate at two arbitrary frequencies and be realized on double‐sided parallel‐strip line (DSPSL). One of the advantages of the DSPSL is easy realization of high impedance transmission line. The circuit design parameters are derived using the even and odd mode analysis. The measured results show a good performance at 3 and 5.77 GHz. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:1898–1900, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26952

Biplanar Monopole With DSPSL Feed and Coupling Line for Broadband Mobile Phone

A biplanar monopole with a double-sided parallel strip line (DSPSL) feed and coupling line for broadband mobile phone is presented. The proposed antenna consists of a DSPSL feed and a coupling line, suitable for broadband operation (824-960/1710-2620 MHz). It just requires a small area of 15 × 40 mm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> on the circuit board, and it is configured along the boundary of the no-ground portion so that it can save much area, on which other electronic components can be put. The antenna is formed by a short strip line at the back side and a long strip line at the front. The overlapping part of them forms the DSPSL structure, which leads to a better impedance matching result. The long strip line contributes to cover the lower band (824-960 MHz), while the short strip line generates a resonant mode to cover the upper band (1710-2620 MHz). A coupling line alongside the long strip line and the ground are also formed to make the high resonant mode more effective. Details of the antenna are presented.

Compact wideband differential bandpass filter based on the double-sided parallel-strip line and transversal signal-interaction concepts

Two compact wideband differential bandpass filters based on the double-sided parallel-strip line (DSPSL) and transversal signal-interaction concepts are proposed in this study. Two transmission zeros and good harmonic suppression can be achieved for the first wideband differential DSPSL filter, because of the two transmission paths with different lengths for input/output ports. In addition, another improved common suppression wideband differential DSPSL filter with two 180/ phase inverters is introduced. Four λ /4 shorted lines are added to improve the passband transmission characteristic for the two differential DSPSL filters. Two prototypes with 3/dB fractional bandwidth of 94 and 117.6/, and return loss greater than 15/dB for differential mode are designed and fabricated. The measured results show good agreement with the theoretical expectations.

Compact dual-mode dual-band balun filter using double-sided parallel-strip line

Proposed is a compact dual-band balun filter adopting a double-sided parallel-strip line (DSPSL). The middle conductor plane can be treated as a virtual ground. Then, two sets of short-stub loaded dual-mode resonators on the top and the bottom layer act as two dual-band filters. They are fed by the DSPSL at the input port, and the filters can be excited simultaneously. Meanwhile, an out-of-phase feature is obtained between the two output ports. In addition, the proposed dual-band balun filter has good frequency selectivity which is due to multiple transmission zeros. Finally, a dual-band balun filter sample was designed and fabricated with good agreement obtained between its measured and simulated S-parameters.

Miniaturised dual-band rat-race coupler based on double-sided parallel stripline

A dual-band rat-race coupler is proposed with double-sided parallel stripline topology, phase inverter and E-shaped impedance transformers. The developed component shows a miniaturised size and a flexible frequency ratio of two operating bands. For validation, a prototype operating at 0.9/1.8 GHz has been designed and measured with a very compact configuration and good performance has been obtained.

Differential six-port demodulator

A differential six-port modulator for the 7 - 8 GHz band is reported for the first time. It is composed of a differential six-port correlator with cold-mode field effect transistors used as impedance terminations, controlled via baseband signal on the gate to source terminal. It is fabricated using double-sided parallel-strip lines. The differential modulator has the advantage of low power consumption, compactness and high signal to noise ratio. A prototype has been fabricated and data transmission with 256-quadrature amplitude modulation at 50 Msymbol/s is demonstrated.

A compact planar bandpass filter with wide out‐of‐band rejection implemented by substrate‐integrated waveguide and complementary split‐ring resonator

AbstractA compact planar bandpass filter is presented in this letter, which is implemented by the combination of three different electromagnetic structures, saying, substrate‐integrated waveguide (SIW), square complementary split‐ring resonators (CSRRs) and dumbbells slot.The resonator is formed by a SIW cavity loaded with some complementary split‐ring resonators (CSRRs) on its top metal plane, causing a stopband with a very sharp rejection. Meanwhile, several dumbbells are etched on the bottom plane of SIW just below each CSRR to enhance the coupling. Double‐sided parallel strip line (DSPSL) is also used to excite the SIW and guarantee good propagation between these two different structures. An X‐band prototype is designed and fabricated for demonstration, good agreement is observed between simulation and measurement, indicating a very wide rejection band ranging from 11 GHz to 23 GHz and quite strong suppression to spurious modes. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26079

A Novel Differential Dual-Band Bandpass Filter Based on Stepped-Impedance Double-Sided Parallel-Strip Line

A novel differential dual-band bandpass filter based on a stepped-impedance double-sided parallel-strip line is proposed in this article. In order to suppress the common-mode signal, an H-shaped ground plane is inserted. The simulated and measured results show that the proposed filter operated at 2.4 GHz and 5.8 GHz with the insertion losses of 3.2 dB and 3.5 dB, respectively. Also, the common-mode signal is suppressed to below −30 dB from 1 GHz to 7.5 GHz.

Broadband cloaking of large arbitrary object by Double-Sided Parallel-Strip Line

In this paper, transmission line cloaking for arbitrary objects with different dimensions is presented. Double-sided parallel-strip line network causes electromagnetic waves to be coupled to the network surrounding the object and pass them across it without forward and backward scattering. Using of these unloaded transmission lines makes the simplicity of the structure feasible. Achieving a broadband cloaking condition is the other advantages of the proposed structure. Large object cloaking is provided by the using of a new structure which has an empty space in the center of similar previous structures. Simulation results demonstrate the quality of cloaking for different dimensions in conventional and proposed structures.

A New Dual Band Power Divider with Extreme Power Dividing Ratio

This paper presents the design of a new dual band power divider realized on double-sided parallel-strip line (DSPSL). The proposed structure mainly features a simple planar structure with extreme power dividing ratio, wide bandwidth, excellent isolation and frequency-independent output phase performance for dual band application. Closed-form equations are derived for design parameters. For verification purpose, the simulated and measured results of a dual band power divider with power dividing ratio of 20:1 are shown.

SUPER-WIDEBAND PRINTED ASYMMETRICAL DIPOLE ANTENNA

The proposed dipole antenna consists of two printed strips with unequal lengths and is fed by a coplanar strip (CPS) line. As the antenna parameters and port impedance are properly selected, a super wide operating band (jS11j < i10dB) of 3.5 to 20.0GHz is realized. Antenna samples were fabricated using standard PCB process. The area of the constructed dipole antenna is 40:0£5:0mm 2 . The S-parameter measurement was performed via a transition (CPS to double-sided parallel strip line) and transformer (190 to 50Ohm). The measured fractional bandwidth achieved 139.3% (from 3.4 to 19.0GHz) as predicted, over which the antenna peak gain is better than 0dBi.

Compact Planar Magic-T Based on the Double-Sided Parallel-Strip Line and the Slotline Coupling

Two compact planar magic-T structures implemented on the double-sided parallel-strip line (DSPSL) and the slotline coupling are proposed and demonstrated. Due to a metallic ground inserted into the middle of the substrate for the double-sided parallel-strip line, the E-plane DSPSL power divider thus shows an intrinsic 180° out-of-phase characteristic between the two input/ output ports. A transition between slotline and DSPSL is utilized to realize the H-plane input/output port of the magic-T. The equivalent circuits are derived for the design of the proposed planar multilayer magic-T. Good agreement between the measured and simulated results indicates that the fractional bandwidths for the two planar magic-T structures are 42.8% and 43.8%, respectively, while the amplitude and phase imbalance are less than 0.22 dB and 1.5°.

The Backfire-to-Broadside Symmetrical Beam-Scanning Periodic Offset Microstrip Antenna

A backfire-to-broadside beam-scanning antenna with a periodic structure is described. The proposed antenna consists of the offset double-sided parallel-strip lines (DSPSL). The characteristics of the offset DSPSL have been studied, and then a series of offset DSPSL have been applied as the periodic antenna with a backfire-to-broadside symmetrical beam scanning capability. Both in plane and plane, main beams symmetrically steer from the backfire direction to the broadside direction with the increase of the operating frequency. The fractional impedance bandwidth has been broadened to nearly 50% by using the offset DSPSL structure.

A Novel Ultra-Wideband Differential Filter Based on Double-Sided Parallel-Strip Line

In this letter, double-sided parallel-strip line (DSPSL) has been used to build a novel differential filter with ultra- wideband (UWB) response. Swap structures, based on DSPSL, are employed in the design to realize 180° phase shift. So the swap structures can realize the conversion between differential- and common-mode. Utilizing the characteristic, the input common- mode signals will be cancelled at the center of the filter, while the input differential-mode signals can propagate in the proposed filter. The proposed new differential filter was calculated in analytical method, and was simulated by the full-wave electromagnetic simulator, and was validated by the measurement. The last results show they have a good in-band and out-band performance. With fractional bandwidth of 110% centered at 3 GHz, the differential-mode signals can propagate with UWB frequency response, while the common-mode signals are suppressed below -20 dB in the whole frequency band.

Formula Derivation and Verification of Characteristic Impedance for Offset Double-Sided Parallel Strip Line (DSPSL)

Double-sided parallel strip line (DSPSL) is a versatile microwave transmission line. With an offset, it allows for large variations of the characteristic impedance and therefore flexibility for the design of novel microwave devices. In this letter, a formula for the characteristic impedance of DSPSL is derived by the fuzzy EM method and verified by commercial software. Very good agreement is observed.