Corrugated Ground Plane Research Articles

Reduced-Size Series-Fed Two-Dipole Endfire Antenna

The conventional series-fed endfire dipole antenna has a wide impedance bandwidth and is inexpensive to manufacture. However, it has a disadvantage: its size is large because of the large inter-dipole spacing, which is required to satisfy the endfire condition for good antenna radiation characteristics. Here, we propose a two-dipole endfire antenna with a reduced size. The miniaturized endfire antenna was designed using a meander line to reduce the interdipole spacing while ensuring that the endfire condition was satisfied. Furthermore, the overall width of the antenna was reduced using a bent dipole and a corrugated ground plane. The electrical size of the proposed antenna was only 0.33

Analytical Modeling of Metamaterial Differential Transmission Line Using Corrugated Ground Planes in High-Speed Printed Circuit Boards

An analytical model for metamaterial differential transmission lines (MTM-DTLs) with a corrugated ground-plane electromagnetic bandgap (CGP-EBG) structure in high-speed printed circuit boards is proposed. The proposed model aims to efficiently and accurately predict the suppression of common-mode noise and differential signal transmission characteristics. Analytical expressions for the four-port impedance matrix of the CGP-EBG MTM-DTL are derived using coupled-line theory and a segmentation method. Converting the impedance matrix into mixed-mode scattering parameters enables obtaining common-mode noise suppression and differential signal transmission characteristics. The comprehensive evaluations of the CGP-EBG MTM-DTL using the proposed analytical model are also reported, which is validated by comparing mixed-mode scattering parameters Scc21 and Sdd21 with those obtained from full-wave simulations and measurements. The proposed analytical model provides a drastic reduction of computation time and accurate results compared to full-wave simulation.

Mechanically Pattern-Reconfigurable Bended Horn Antenna for High-Power Applications

In this letter, a mechanically pattern-reconfigurable antenna is presented to achieve various half-power beamwidth for high-power applications. A bended H-sectoral horn antenna with two movable metallic flaps is presented to change the aperture length in the H-plane direction in order to provide reconfigurable half-power beamwidth starting from 58.7° to 16.5°. Moreover, the horn radiating aperture is integrated into a corrugated ground plane to increase the E-plane radiation pattern gain. The antenna is energized with an effective power source of 1.9 kW showing the capability of the antenna to handle high-power microwave signals within a certain frequency range.

Miniaturized Dual-Band Aperture Coupled Microstrip Antenna Using Corrugated Ground

A novel dual-band aperture coupled microstrip antenna with corrugated ground plane is proposed to im- prove radiation performance in this letter. The dual-band operation is obtained by embedding an S-shaped slot in the radiating patch. To achieve the high gain and the reduced half power beam bandwidth (HPBW) for each frequency, the double- periodic corrugated ground plane is utilized. Both the simulation and measurement results show that the gain of the proposed antenna is increased by 4.7 dB and 5.6 dB at each frequency correspondingly and the half power beam width (HPBW) of E-plane is reduced by 140 degrees and 150 degrees, respectively.

Low-Profile Antenna With Elevated Toroid-Shaped Radiation for On-Road Reader of RFID-Enabled Vehicle Registration Plate

A low-profile antenna installed on the road surface for RFID-enabled vehicle communication is presented. The antenna in this application operates as on-road sensor for vehicles identification. To that end, the antenna is required to have an elevated toroid-shaped radiation, so that the reader can easily interrogate an RFID-enabled vehicle license. The antenna is designed using a capacitive-loaded inverted-F radiator, which has an omnidirectional radiation in the azimuth plane. To adjust the radiation pattern to the required elevation above the road surface, and isolate the radiation from the effects of variable road conditions, a corrugated ground plane with perturbed surface impedance is used underneath the radiator. The antenna’s configuration is verified by full-wave finite difference time domain simulations with various road surface conditions. A prototype antenna is then developed and tested in realistic field scenarios as on-road sensor for vehicles identification. The results show that the antenna possess more than 15 dB return loss, more than 1.5 dBi gain, vertical polarization, and desirable radiation pattern from 880 to 960 MHz, which is the standard band licensed for RFID-enabled plates. The antenna also successfully communicates with an RFID-enabled vehicle registration plate.

X-Band Circularly Polarized Saddle Radiation Pattern Satellite Antenna

This article presents a new technique to excite a waveguide as a feed for a satellite antenna in low Earth orbit. In the first step, the potential ability of an annular probe antenna as a feed in a cylindrical waveguide is presented to produce circular polarization; scientific concepts are presented about this ability. Also, a method is studied to determine the dyadic Green function inside the cylindrical waveguide when an arbitrary probe is embedded in the waveguide. In the second step, according to Poynting’s theorem, the radiation power for the annular probe in the waveguide is calculated. Subsequently, the probe impedance due to the radiation power is determined in the waveguide. Another requirement is the creation of a wide radiation pattern that is realized by a corrugated ground plane installed on the aperture of the waveguide; this structure is known as a choke ring antenna. As the elevation angle increases, the choke ring antenna gain increases until the maximum gain for a certain elevation angle occurs. This feature leads to a saddle radiation pattern for a higher level of coverage of subscribers on Earth until a greater area on Earth is available for the satellite. After theoretic works, a simulated sample of this antenna confirmed the theoretic formulas. To validate the effectiveness of the proposed method in creating circular polarization modes in a cylindrical waveguide and shaping of the pattern as a saddle radiation pattern, a choke ring antenna is designed and fabricated. The theoretic, simulated, and fabricated results have good agreement.

Planar hyperlens based on a modulated graphene monolayer

The canalization of terahertz surface plasmon polaritons using a modulated graphene monolayer is investigated for subwavelength imaging. An anisotropic surface conductivity formed by a set of parallel nanoribbons with alternating positive and negative imaginary conductivities is used to realize the canalization regime required for hyperlensing. The ribbons are narrow compared to the wavelength, and are created electronically by gating a graphene layer over a corrugated ground plane. Good quality canalization of surface plasmon polaritons is shown in the terahertz even in the presence of realistic loss in graphene, with relevant implications for subwavelength imaging applications.

High-Efficiency, High-Gain, Broadband Quasi-Yagi Antenna and Its Array for 60-GHz Wireless Communications

This paper introduces a high-efficiency, high-gain, broadband quasi-Yagi antenna, and its four-element array for use in 60-GHz wireless communications. The antenna was fed by a microstrip-to-slotline transition consisting of a curved microstripline and a circular slot to allow broadband characteristics. A corrugated ground plane was employed as a reflector to improve the gains in the low-frequency region of the operation bandwidth, and consequently, to reduce variation. The single antenna yielded an impedance bandwidth of 49 to 69 GHz for |S11| 12.0 dBi while the array exhibited a bandwidth of 52 to 68 GHz and a gain greater than 15.0 dBi. Both proposed designs had small gain variations (±0.5 dBi) and high radiation efficiency (>95%) in the 60-GHz bands. The features of the proposed antenna were validated by designing, fabricating, and testing a scaled-up configuration of the single antenna at the 15-GHz band. The measurements resulted in an impedance bandwidth of 13.0 to 17.5 GHz for |S11|< 10 dB, a gain of 10.1 to 13.2 dBi, and radiation efficiency in excess of 88% within this bandwidth. Additionally, the 15-GHz antenna yielded quite symmetric radiation profiles in both E- and H-planes, with a high front-to-back ratio.

A Compact Multipath Mitigating Ground Plane for Multiband GNSS Antennas

This paper presents the design of a novel multipath mitigating ground plane for global navigation satellite system (GNSS) antennas. First, the concept of a compact low multipath cross-plate reflector ground plane (CPRGP) is presented. In comparison with the choke ring and electromagnetic band gap (EBG) ground planes, the proposed CPRGP has compact size, low mass, wide operational bandwidth, and simple configuration. The proposed CPRGP is then integrated with a circularly polarized dual-band GNSS antenna in order to assess the multipath mitigating performance over two frequency bands. Measurement results of the proposed CPRGP with GNSS antenna achieves a front-to-back ratio (FBR) over 25 dB at L1 (1.575 GHz) and L2 (1.227 GHz) bands and maximum backward cross-polarization levels below <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex Notation="TeX">${-}$</tex></formula> 23 dB at both bands. Antenna phase center variation remains less than 2 mm across both L1 and L2 bands. Furthermore, the performance comparison of the proposed CPRGP with the commercially available pinwheel antenna and the shallow corrugated ground plane is presented, showing the advantages of CPRGP for high precision GNSS applications.

A New Compact Aperture-Coupled Microstrip Antenna With Corrugated Ground Plane

A new kind of aperture-coupled microstrip antenna with enhanced gain and radiation pattern is presented in this letter. By substituting the corrugated ground plane for the flat ground plane of conventional aperture-coupled microstrip antenna, the proposed antenna with high performance is obtained by the constructive superposition of the electric fields radiated by the patch and grooves. Both the simulation and measurement show that compared to the conventional antenna, the gain is increased by 5.3 dB, the front-to-back ratio (F/B) is increased by 6 dB, and the half-power beamwidth (HPBW) of E-plane is reduced by 125°. Moreover, the proposed antenna features its compactness.

Self-Generation of Circular Polarization Using Compact Fabry–Perot Cavity Antennas

A new configuration of a compact self-polarizing Fabry-Perot (FP) cavity antenna is presented. It is excited in single-linear polarization at 45 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">°</sup> and radiates in circular polarization. It consists of a polarizing FSS (used to ensure the polarization conversion) and a corrugated ground plane (designed to guarantee the resonance conditions for both incident orthogonal linear polarizations). A compact shielded FP antenna with an aperture of 1.62 λ <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0</sub> is optimized and fabricated in <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">S</i> -band to validate the concept at 2.5 GHz. A 3-dB axial-ratio bandwidth of about 1.9% is achieved with an antenna height of only 0.8 λ <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0</sub> . The experimental results are in good agreement with the simulations. This antenna configuration is attractive for narrowband applications, like the space ones in <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">C</i> - or <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">S</i> -bands.

A CPW-FED ULTRA-WIDEBAND PLANAR INVERTED CONE ANTENNA

This paper presents a CPW-fed planar inverted cone an- tenna (PICA) for ultra-wideband (UWB) communication applications. The proposed PICA provides a conventional monopole type omnidirec- tional radiation pattern, and it utilizes the advantages of the coplanar- waveguide (CPW) to simplify the structure of the antenna into a sin- gle metallic level. To improve radiation characteristics, a tapered and corrugated ground plane is used. In addition, the PICA's radiating element with three self-similarity holes is attempted to enhance per- formance of the antenna. The simulated and measured results demon- strate that the proposed PICA achieves a broad impedance bandwidth from 1.3GHz to 11GHz within the magnitude of S11 (dB) less than i10dB and maintains nearly omnidirectional radiation characteristics.

A Low-Multipath Wideband GPS Antenna With Cutoff or Non-Cutoff Corrugated Ground Plane

We compare the performance of the classic global positioning system (GPS) choke ring ground plane with a new shallower design. Both the choke ring and the new ground plane are here designed to operate uniformly between 1.15 GHz and 1.60 GHz while maintaining the required low-multipath performance in the whole bandwidth. To achieve reception in this wide range of frequencies, the radiating element chosen is a droopy bowtie turnstile. A classic choke ring is composed of deep concentric rings on a flat circular metal ground plane. We have modeled the choke ring as a metal corrugated surface of depth d such that lambda/4lesdleslambda/2 , operating at cutoff: the multipath suppression (i.e., the proper RHCP/LHCP pattern shaping) is obtained by eliminating the surface wave on the ground plane in a certain frequency band. When shallower concentric rings of depth dleslambda/4 are used, the corrugated surface operates at non-cutoff: the required multipath rejection can be achieved by cancellation (destructive interference) rather than suppression of surface waves. The comparisons performed in this study include theory, numerical simulations, and hardware tests. Our results show that both configurations, when properly optimized, are good candidates for reception of modernized GPS, GLONASS, and GALILEO satellite signals from GPS permanent stations.

Propagation Analysis of Circular Surface Waveguides with a Periodically Corrugated Ground Plane

SUMMARY A mode-matching technique in conjunction with the Floquet theorem is proposed to analyze the propagation characteristics of periodic circular surface waveguides. The circular waveguides are coated outside with a multilayered dielectric and have a ground plane with periodic corrugation of arbitrary profile. Three different ground corrugation profiles are examined to demonstrate the influences of the corrugation shape, depth, and width, dielectric thickness, and relative permittivity on bandstop characteristics.

DESIGN OF AN ACTIVE INTEGRATED ANTENNA FOR A PCMCIA CARD

This paper presents the design and implementation of an Active Integrated Antenna (AIA) using a Voltage Controlled Oscillator (VCO) for applications in the Industrial Scientific Medical band (2.4 ÷ 2.4835 GHz). Surface Mounting Device (SMD) technology has been applied in the realization of the passive and active components, and low cost FR-4 dielectric slabs have been employed for the integration of the antenna and the active/transmissive circuits, residing, respectively, on the opposite faces of a Personal Computer Memory Card International Association (PCMCIA) card. The proposed layout makes use of a properly corrugated ground plane, i.e., a High Impedance Ground Plane (HIGP), to improve the antenna performances and to minimize the coupling between the radiating component and other possible radiating elements and/or electronic circuits residing nearby. The analysis and the design of the radiating element with the HIGP are based on a rigorous full wave Method of Moment (MoM) formulation developed in the Spectral Domain (SD), while the design of the active circuitry is developed through the commercial tool AWR Microwave Office. The final design of the component is obtained hybridizing the 254 Bilotti, Urbani, and Vegni two methods and applying a Genetic Algorithm (GA) optimization tool in order to take advantage of the HIGP, while keeping the geometrical dimensions of the antenna suitable for mounting on a PCMCIA card, and maintaining the antenna performances acceptable. The measured results show the performances of the VCO, an antenna gain of 19.4 dBi and an increased front-to-back radiation ratio compared to the one of the same antenna mounted on a standard Perfect Electric Ground Plane (PEGP). This result, thus, demonstrates the minimization of the interferences between the designed antenna and other possible radiating and transmissive devices residing nearby.

Compact dual-printed inverted-F antenna diversity systems for portable wireless devices

Dual-printed inverted-F antenna diversity systems for terminal devices operating at 5.2 GHz under both switched and combining schemes are presented. Diversity performance is evaluated by means of the calculated envelope correlation coefficient, the mean effective gain and the effective diversity gain of the two antennas. An investigation into the effect of the antennas' placement and of the corrugated ground plane on the performance of the system has also been conducted. It is shown that many configurations can provide uncorrelated signals of the same power level, but with significantly different radiation pattern complementarity, antenna efficiency, and effective diversity gain.

An efficient method for the TE- and TM-fields from an array on a corrugated ground plane

The far-field for the scalar te- and TM-cases is computed in three dimensions for a system radiating into the upper half-space. An array of sources is situated on the boundary and in between a number of infinite and equidistant rectangular grooves. Since the primary objective is to study the exterior problem, the sources are assumed to be known. Fourier transformation is used to derive matrix equations for the set of two-dimensional problems that correspond to polar directions in the far-field. When comparing the results for the two polarizations, the influence of the grooves in the ground plane is found to be weaker for the TM-case. The effects of certain singularities in the Fourier integrals are investigated by means of asymptotic methods.