Patterned Ground Plane Research Articles

A Novel Compact Dual-Functional Circuit With Differential-Mode Equalization and Broadband Common-Mode Suppression Using Patterned Ground Plane

A Novel Compact Dual-Functional Circuit With Differential-Mode Equalization and Broadband Common-Mode Suppression Using Patterned Ground Plane

A bandwidth and gain enhancement for microstrip antenna based on metamaterial

AbstractAn ameliorated ultrawide band (UWB) and high‐gain microstrip antenna based on planar metamaterial is presented and discussed in this paper. The proposed antenna with a compact size of 32 × 28 × 0.794 mm3 has mesh‐shaped patch and patterned ground plane with crossed strip gaps. By means of novel planar metamaterial structure, impedance bandwidth and gain own a significant improvement. The simulations show that the antenna has a super‐wide band (less than −10 dB), from 3.06 GHz to 36.4 GHz, covering the entire UWB frequency band (from 3.1 GHz to 10.6 GHz) set by FCC. Within the operating band of concern, the antenna gain can reach as high as 8.02 dB. Due to the surface wave coming from the patterned patch and ground plane, the antenna presents end‐fire directional radiation in the higher frequency region. To validate the simulation results, a prototype is fabricated and measured. And the measured results are in good agreement with the simulation results. It is obvious that advantages mentioned above will enable the proposed antenna to be well applied in the short‐range wireless communication system.

A microstrip photonic crystal bandgap device with a switchable negative epsilon plasma element

AbstractWe present a microstrip photonic bandgap (PBG) device with a switchable plasma element integrated into the patterned ground plane. A pulsed laser plasma is generated in one of the PBG cavity structures creating a medium having an effective negative permittivity in the 8–10 GHz frequency range due to the high plasma density ne = 1017 cm−3. The PBG structure consists of a linear array of seven cavities along the length of the microstrip manufactured by removing cylindrical portions of copper in the ground plane. The plasma is produced in the central cavity of the PBG array and recombines over times of several microseconds allowing for the characterization of the microstrip transmission over a range of plasma density. The results confirm a switchable transmission due to plasma interactions with the electromagnetic field within the PBG structure.

Performance of Groundplane Shaping in Four-Element Dualband MIMO Antenna

This work presents performance of groundplane shaping and its effect in four element dualband multiple input multiple output (MIMO) antenna. This proposed four element dualband MIMO antenna consists of four bowtie dipole antenna which operates at 1800 MHz (low frequency) and 2300 MHz (high frequency). This proposed four element dualband MIMO antenna occupies a 270 x 210 x 100 mm 3 of FR 4 substrate. We use four types of groundplane pattern i.e. full groundplane, cornered spatial groundplane,crossed middle groundplane, and spiral groundplane. These various grounplane patterns influence the performance of main parameters of dualband MIMO antenna. Cornered spatial groundplane pattern yields a largest bandwidth (VSWR ≤ 2) 282 MHz or 15.24% of center frequency at low frequency. Full groundplane pattern creates 135.2 MHz at high frequency. In addition, cornered spatial groundplane pattern also generates a lowest VSWR that is valued 1.21 at both low frequency and high frequency. The S parameters, basically both cornered spatial and full groundplane pattern produce a better return loss than two others. All four groundplane patterns deliver equally a mutual coupling parameter.The last, this proposed four element dualband MIMO with various groundplane patterns gives a good farfield properties i.e. gain, radiation pattern, H-E field.

Design & Simulation of Fractal Antenna for Wi-Max Operation

A metamaterial-based novel compact microstrip antenna is presented for Wi-Max applications. The antenna consists of a layer of metamaterial made by etching a crossed-shaped slots, on the the ground plane, respectively. The shunt inductance developed due to the patterned ground plane lead to the lefthanded behaviour of the metamaterial. The proposed antenna has a compact size of 45.4 × 31.6 × 1.6 and is fed by a 50 Ω microstrip line. Radiating patch is fractal antenna of star shape with 6mm side length. The impedance bandwidth (−10 dB) is from 3 GHz to more than 14 GHz with maximum radiation in the horizontal plane and tends towards a directional pattern as the frequency increases. Maximum gain 15.8533db obtained from fractal antenna.

Common-mode noise mitigation using ring resonator patterned ground plane for WiMAX and TD-LTE applications

This paper proposes a novel miniature bandstop filter for common-mode noise suppression in WiMAX and TD-LTE devices using ring resonator patterned defected ground structure (DGS). The proposed filter consists of two layers; coupled microstrip lines on the top layer, ring resonator based DGS on the bottom layer and the two layers are separated by FR4 dielectric substrate. Due to asymmetry in the PCB layout, the differential signal is converted to common-mode signal. The common-mode signal is considered as a noise in differential signaling systems and it must be suppressed to preserve the differential signal integrity. The filter provides differential insertion loss of less than −2dB for frequencies up to 5GHz. A peak insertion loss of −34dB is observed for the common-mode signal at 3.5GHz and a −20dB stop bandwidth of 580MHz from 3.14 to 3.72GHz. The common-mode to differential mode conversion is below −70dB for frequencies up to 5GHz. The common-mode noise suppression is improved by 72% in the time domain. The fractional bandwidth is 17%. The size of the filter is 0.41λg×0.2λg. From the eye-diagram, the values of MEO and MEW are 0.93V, 0.58ns. The proposed filter is fabricated and the measured results have good correlation with the simulated results.

Inverted‐F antenna with periodic patterned structures for multiband applications

AbstractBy introducing periodic patterned structures to planar inverted‐F antenna (PIFA), a novel triple‐band antenna has been achieved and is presented.The transmission line model for periodic patterned ground plane loaded PIFA is extracted. Simulations are confirmed by the experimental results, which ensure that the proposed antenna is well suited for WLAN and WiMAX applications. © 2013 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:1365–1367, 2013; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27597

Single-Layer Microstrip High-Directivity Coupled-Line Coupler With Tight Coupling

A novel symmetrical coupled-line circuit structure without patterned ground plane is proposed to design tight-coupling high-directivity couplers, which would be found in numerous applications in a microstrip RF front end because of its simple structure and inherent excellent compatibility. Based on a traditional even- and odd-mode technique, closed-form mathematical equations for both circuit electrical parameters and scattering parameters are obtained. Due to the use of two coupled-line sections placed in the vertical direction, the directivity of this novel coupler without any other compensation techniques can be enhanced while maintaining tight-coupling performance of almost 3 dB. For demonstrative purposes, three typical full-wave simulation examples with realized physical dimensions in microstrip technology are presented, indicating high directivity and tight coupling coefficient. Finally, a practical microstrip coupled-line coupler is designed and fabricated to operate at approximately 2 GHz. The measured results show good return loss, quadrature phase characteristics, high directivity, and strong coupling performances.

A novel wide-band hybrid coupler using coupled-line power divider and improved coupled-line phase shifter

A novel hybrid coupler aiming for wide-band applications is proposed in this paper. This hybrid coupler consists of a broadband Wilkinson coupled-line power divider and an improved wide-band coupled-line phase shifter. Taking advantage of the coupled-line section, the power divider achieves both compact circuit configuration and wide-band performance. In lieu of patterned ground plane and lumped capacitors, the coupled-line phase shifter can be constructed on a single-layer printed circuit board for wide-band operation. For this proposed phase shifter, the scattering parameters (S-parameters) expressions are derived and the optimal structural design parameters for achieving zero reflection coefficients are highlighted. After carefully choosing the circuit parameters, a new wide-band hybrid is constructed by combining a power divider and the proposed phase shifter. To verify against the theoretical calculation in terms of S parameters and phase information, a hybrid operating at 3 GHz is designed, simulated, and fabricated through microstrip technology. Close agreement is obtained between simulation and measurement results.

Note: Cryogenic microstripline-on-Kapton microwave interconnects

Simple broadband microwave interconnects are needed for increasing the size of focal plane heterodyne radiometer arrays. We have measured loss and crosstalk for arrays of microstrip transmission lines in flex circuit technology at 297 and 77 K, finding good performance to at least 20 GHz. The dielectric constant of Kapton substrates changes very little from 297 to 77 K, and the electrical loss drops. The small cross-sectional area of metal in a printed circuit structure yields overall thermal conductivities similar to stainless steel coaxial cable. Operationally, the main performance tradeoffs are between crosstalk and thermal conductivity. We tested a patterned ground plane to reduce heat flux.

A FREQUENCY SELECTIVE ABSORBING GROUND PLANE FOR LOW-RCS MICROSTRIP ANTENNA ARRAYS

An e-cient strategy for reducing the signature of an antenna is to substitute the conventional solid ground plane with a patterned ground plane thus letting the incoming energy to pass through the structure except over the operating band of the antenna. However, in a real environment, the energy ∞owing through the FSS (Frequency Selective Surface) can be intercepted by eventual scatterers located behind the antenna, so to nullify the RCS (Radar Cross Section) reduction. To overcome this drawback, a novel composite structure is proposed which is able to dissipate such energy by placing a thin absorbing layer below the FSS ground. It is shown that a careful analysis has to be performed to accomplish this goal since the transparent antenna array and the backing absorber strongly interact and thus they cannot be separately designed. The optimal value of the foam spacer thickness between the FSS ground and the absorbing layer is investigated by an e-cient equivalent transmission line approach. Criteria for enlarging the low-RCS band with respect to the free space design are also provided. An antenna array prototype backed by the thin multilayer structure is flnally manufactured and tested.

Reconfigurable RF Quadrature Patch Hybrid Coupler

A highly reconfigurable radio frequency patch hybrid coupler with a simple topology is presented for the first time. Due to the introduction of lumped equivalent circuit and flexibility of varactor loaded patterned ground plane, the complex reconfigurability in port arrangement and coupling coefficient can be implemented. Varying the capacitance across different planes allows the electronic switching between different operating modes of the patch hybrid coupler. When the auxiliary patch and patterned ground plane is placed closer to the two output ports, tunable coupling coefficient can also be implemented by changing the capacitance. This results in wide band reconfigurability for the coupling coefficient range. For demonstration purposes, a patch hybrid coupler operating at 2.4 GHz is designed and measured to validate the port reconfigurable concept. Also, a patch hybrid coupler with tunable coupling coefficient operating at 3.5 GHz is designed, fabricated, and measured. This circuit gives a reconfigurable coupling coefficient ranging from -4.2 to -10 dB while maintaining good performance.

Impedance matching and spurious-response suppression in stepped-impedance low pass filters

In this article, the method of least squares is used to design a stepped-impedance low pass filter with arbitrary specifications on the pass, transition, and stop bands, having different input and output impedances.The equivalent circuits of the line sections and step discontinuities are used (with appropriate dispersion relations) to determine the filter transmission matrix and the scattering parameters, which are then used to construct an error function. Its minimization is performed by the combination of particle swarm optimization and conjugate gradient methods. The conversion of lumped filter designs, by Butterworth, Chebyshev, and elliptic methods to the equivalent microstrip filters (namely conversion of L and C components to strip lines) may be difficult to realize. The proposed method of least squares procedure leads to the design characteristics having sharper transition bands and a wider pass band. The rectangular split ring resonators, as patterned ground plane, will remove the spurious responses in the stop band and actually increase the stop bandwidth. The results obtained by full-wave simulation softwares, fabrication, and measurements verify the proposed method for low pass stepped-impedance filter design. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26184

Dual Grid Array Antennas in a Thin-Profile Package for Flip-Chip Interconnection to Highly Integrated 60-GHz Radios

We examine the current development of highly integrated 60-GHz radios with an interest in antenna-circuit interfaces. We design and analyze grid array antennas with special attention to the differential feeding and the patterned ground plane. More importantly, we integrate two grid array antennas in a package; propose the way of assembling it to the system printed circuit board; and demonstrate a total solution of low cost and thin profile to highly integrated 60-GHz radios. We show that the package in low temperature cofired ceramic (LTCC) technology measures only 13×13×0.575 mm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sup> ; can carry a 60-GHz radio die of current and future sizes with flip-chip bonding; and achieves good antenna performance in the 60-GHz band with maximum gain of 13.5 and 14.5 dBi for the single-ended and differential antennas, respectively.

Frequency-Agile Patch Element Using Varactor Loaded Patterned Ground Plane

This paper presents, for the first time, a method to realize the concept of frequency agility on patch-type circuits, which have found more applications at very high frequencies because of its simple structure. A patterned ground plane has recently been proposed for size reduction of patch-type circuits making them more favorable at lower frequencies. An additional auxiliary patch on the ground plane is proposed in this paper as a mechanism to change the capacitance between the upper patch and ground plane. The patterned ground plane loaded with tunable capacitors is applied to the patch element to realize frequency agility. For demonstration, a frequency-agile rectangular patch hybrid coupler with a varactor loaded patterned ground plane is designed to operate over a frequency range of 50% (from 1.5 to 2.5 GHz) with good return loss, small amplitude imbalance, and quadrature phase characteristics.

MODIFIED BROADBAND SCHIFFMAN PHASE SHIFTER USING DENTATE MICROSTRIP AND PATTERNED GROUND PLANE

In this letter, a modifled broadband 90 - phase shifter is proposed. By using a dentate microstrip and a patterned ground plane, an extremely tight coupling can be obtained, and consequently a constant phase shift over a wide bandwidth can be achieved. To verify the proposed idea, a topology is implemented, the measured results of a phase difierence of 90 § 5 - in 79.5% bandwidth, better than 10dB return loss across the whole operating band, are also given. The measurement results agree well with the full-wave electromagnetic simulated responses.

Designing a very wide stopband microstrip bandpass filter with patterned ground plane

In this article, a microstrip bandpass filter with a very wide stopband is provided.Based on our previous published ultra-wide stopband bandpass filter, this proposed filter can extend the stopband range by adopting the patterned ground plane. The full-wave electromagnetic simulator IE3D is used, and the prototype of the bandpass filter is fabricated and measured. Comparisons of simulated results and experimental data are shown; moreover, good match validates the proposed filter. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52:2845–2847, 2010; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.25611

Design and implementation of a high‐performance V‐band CMOS bandpass filter

AbstractIn this article, we demonstrate a low‐insertion‐loss V‐band (50–75 GHz) bandpass filter with two finite transmission zeros by standard 0.13 μm CMOS technology. The proposed filter architecture has the following feature: the low‐frequency transmission‐zero and the high‐frequency transmission‐zero can be tuned by the series‐feedback capacitor Cs and the parallel‐feedback capacitor Cp, respectively. Besides, low‐insertion‐loss is achieved by adopting thick microstrip‐line (MSL) with optimized ground‐plane pattern as the needed inductors to minimize the metal and substrate loss. This filter achieved insertion‐loss (1/S21) lower than 3 dB over the frequency range of 52.2–76.7 GHz, input return loss (S11) better than −10 dB over the frequency range of 50.2–80.6 GHz, and output return loss (S22) better than −10 dB over the frequency range of 50.2–77.3 GHz. The minimum insertion‐loss was 2.18 dB at 63.5 GHz, an excellent result for a V‐band CMOS bandpass filter. The chip area was only 0.466 × 0.307 mm2, i.e., 0.143 mm2, excluding the test pads. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52: 309–316, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24935

Analysis and design of novel dual‐band branch line coupler with patterned ground plane

AbstractThis article presents the novel dual‐band planar 90° branch line coupler with patterned ground plane, sometimes referred to as ‘defected ground structure.’ In the new layout, two cross coupling branches are added to the conventional branch line coupler. The additional branches make the design of dual‐band coupler at two arbitrary bands more flexible. Moreover, the used patterned ground plane makes an implementation of high impedance microstrip line easy and increases the electrical length of microstrip line. The basic principles of the novel coupler are analyzed and the design procedure is presented. For method validation, a dual‐band microstrip coupler operating at 2.1 GHz and 3.6 GHz was designed, tested, and analyzed. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 1000–1005, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24246

Size-Reduced Rectangular Patch Hybrid Coupler Using Patterned Ground Plane

This paper presents, for the first time, the design of a size-reduced rectangular patch hybrid coupler. Different types of compact rectangular patch hybrid couplers with different ground plane patterns are described. For demonstration, two compact rectangular patch hybrid couplers are designed to operate at 3.5 GHz. They are measured to have 30.1% and 33.3% bandwidth with 67.3% and 72.3% size reduction compared with the optimized one without patterned ground plane.