Edge Of Ground Plane Research Articles

UWB Staircase-Profile Printed Monopole Design

In printed monopoles, the current distribution along the lower monopole sheet and upper groundplane edges can be made analogous to a transmission line distribution by an appropriate antenna feed design. Accordingly, the VSWR < 2 impedance bandwidth upper frequency limit can be estimated for staircase-profile printed 2D ultrawideband (UWB) monopoles. Following this guideline, three tailored-bandwidth prototypes are designed, implemented and measured. They retain their length and width while multiplying their upper frequency (4.87, 8.7, and 15.15 GHz) by the number of monopole profile steps (1, 2, and 3). The deviation is found mainly below 13% in relation to the reference formula. The concept of angular range based on pattern stability factor (PSF) is introduced to compare the solid angle of UWB pattern stability operation when increasing the bandwidth. The angular range degradation versus impedance bandwidth improvement shows all the possible performance levels of the antennas. Thus, the design of UWB printed monopoles is approached from both points of view, i.e., impedance bandwidth and pattern stability.

Printed Monopole Slot Antenna for Internal Multiband Mobile Phone Antenna

A new internal multiband mobile phone antenna formed by two printed monopole slots of different lengths cut at the edge of the system ground plane of the mobile phone is presented. The antenna can generate two wide bands centered at about 900 and 2100 MHz to cover the GSM850/GSM900/DCS/PCS/UMTS bands and the 2.4-GHz WLAN band. Further, the antenna has a simple planar structure and occupies a small area of only. It is also promising to bend the antenna into an L shape to reduce its volume occupied inside the mobile phone. Good radiation characteristics are obtained over the two wide operating bands.

Printed compact S‐shaped monopole antenna with a perpendicular feed for penta‐band mobile phone application

AbstractA printed compact S‐shaped monopole antenna for penta‐band mobile phone application is presented. The S‐shaped monopole antenna has a uniplanar structure and can be printed on an FR4 substrate of small size 10 × 45 mm2 to achieve a compact configuration. By mounting the antenna above the top edge of the system ground plane of the mobile phone and feeding it using a perpendicular feed, the antenna occupies a small volume in the top portion of the mobile phone. This makes it especially suited for application in the thin mobile phone in which the embedded internal antenna is required to be small in occupied volume and narrow in width. In addition, the antenna can generate two wide operating bands at about 900 and 2000 MHz to cover the GSM850/900 and DCS/PCS/UMTS operation, respectively. Details of the proposed antenna are presented. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 3172–3177, 2007; Published online in Wiley InterScience (www.interscience.wiley.com).DOI 10.1002/mop.22929

EMC internal GSM/DCS patch antenna for thin PDA phone application

AbstractA promising application of the electromagnetic compatible (EMC) internal patch antenna centered at the top portion of the thin smart phone or personal digital assistant (PDA) phone is presented. The EMC antenna in this study is encircled by an L‐shaped shielding wall, which also serves as part of the antenna's ground plane and is centered above the top edge of the system ground plane. This arrangement is different from the general case of the internal patch antenna mounted on one side of the system ground plane. In this case, with the LCD monitor, battery, and associated electronic components generally mounted on both sides of the system ground plane, the required housing thickness for the PDA phone can be decreased. This makes it easy to achieve a thin PDA phone of thickness about 10 mm only. In addition, the studied antenna uses a simple radiating metal pattern of a long folded strip and a short spiral strip for generating two wide bands for GSM/DCS operation. This simple radiating metal pattern makes it easy to control the antenna's two excited resonant modes for GSM/DCS operation. Also, effects of the user's hand holding the thin PDA phone with the studied antenna are analyzed. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 403–408, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22167

Internal GSM/DCS Antenna Backed by a Step-Shaped Ground Plane for a PDA Phone

A novel internal global system for mobile communication/digital communication system (GSM/DCS) antenna suitable for application in mobile devices such as the Personal Digital Assistant (PDA) phone is presented. The antenna has two radiating strips designed to operate at about 900 and 1800 MHz for GSM/DCS operation, and is backed by and short-circuited to a step-shaped ground plane. With the use of the step-shaped ground plane, which is to be placed at the top edge of the system ground plane of a PDA phone, the antenna can be employed in very close proximity to the possible RF shielding metal cases for battery and associated RF module/circuitry, with almost no degradation in the antenna performances. In addition, the antenna almost occupies no board space in the system ground plane, and is with a very small protruded length (3 mm only in this study) over the top edge of the system ground plane. The antenna is thus very promising to operate as an internal antenna, and in addition, shows an attractive electromagnetic compatibility (EMC) property with nearby conducting or RF elements inside a mobile device.

EMC internal patch antenna integrated with a U‐shaped shielding metal case for mobile device application

AbstractA novel integration design of a shorted patch antenna and a U‐shaped shielding metal case for application in a mobile communication device is presented. The shorted patch antenna is mounted within the dented portion of the U‐shaped shielding metal case, which can provide a coupling‐free space for accommodating electronic components such as the RF modules/circuitry and battery in the mobile device. Thus, in this case, the shorted patch antenna can operate as an internal antenna having an electromagnetic compatibility (EMC) property with nearby electronic components. In addition, with the proposed integration design, the shorted patch antenna is isolated from the two side edges of the system ground plane of the mobile device. Hence, it can be expected that the effects of the user's hand on the performances of the antenna will be suppressed. The proposed integration design applied to a smart phone for Universal Mobile Telecommunications System (UMTS, 1920–2170 MHz) operation is studied. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 1157–1161, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21552

Generation Method of a Calculable Electromagnetic Pulse and its Evaluation

A method and configuration for generating a calculable electromagnetic pulse is proposed in which the electromagnetic pulse is radiated from a small monopole antenna placed near the edge of a semi-infinite ground plane. The monopole antenna is excited by an impulse train. The radiated electric field at a distance from the edge is calculated by the waveform of the excited impulse with the assistance of the Uniform Theory of Diffraction (UTD) to include the effect of diffraction from the edge of the ground plane. The electric field is also reconstructed by signal processing using the complex antenna factor (CAF) of a receiving wide-band antenna. The estimated systematic effects and the agreement of the calculated and reconstructed waveforms show that the generated electromagnetic pulse has a possibility to be used as a reference wave for electromagnetic pulse measurements.

Thin Internal GSM/DCS Patch Antenna for a Portable Mobile Terminal

A novel internal dual-band patch antenna with a small thickness of 3 mm for application in Global System for Mobile Communication/Digital Communication System (GSM/DCS) mobile terminals such as the mobile phone or Personal Digital Assistant (PDA) phone is presented. The patch antenna occupies an area of 15/spl times/60 mm/sup 2/, with its top patch embedded with a simple T-shaped slit, which separates the top patch into two resonant paths to generate two resonant modes for 900/1800 MHz operation. Then, by extending a small portion of the top patch beyond the top edge of the system ground plane of the mobile terminal, the antenna can provide two wide bandwidths covering the GSM/DCS bands. The proposed antenna is experimentally studied, and effects of the extended top-patch portion and the ground-plane length on the obtained bandwidths are discussed.

Shorted elliptical patch antennas with reduced surface waves on two frequency bands

In this paper, a study on the surface waves emission of a shorted annular elliptical patch (SAEP) antenna is presented. This radiator is constituted of an annular elliptical patch having the inner border shorted to the ground plane. The surface wave field excited by the SAEP antenna has been evaluated considering an equivalent magnetic current distribution flowing onto the outer boundary of the patch. It will be demonstrated that the dimensions of the outer elliptical contour can be chosen in such a way that the excitation of the TM/sub 0/ surface wave mode is suppressed on two frequencies. This characteristic makes possible the design of SAEP antennas with reduced surface wave (RSW) emissions on two frequency bands. To validate this result both numerical simulations and measurements will be presented. In particular, it will be shown that when the RSW-SAEP is considered the field strength within the substrate undergoes a faster decay resulting in a reduced mutual coupling in dual band array applications. Furthermore, the effective reduction of the surface waves power minimizes the scattering from the ground plane edges leading in smoother radiation patterns.

Effect of a finite ground plane on microstrip-fed cavity-backed slot antennas

This paper examines the effect of a finite ground plane on microstrip-fed cavity-backed slot antennas. The uniform geometrical theory of diffraction is employed for calculating the diffracted fields from the edges of a slot antenna's finite ground plane. Measured and simulated results are presented to illustrate the edge effect of a finite ground plane on a slot antenna's return loss and radiation pattern. It is demonstrated that the finite ground plane has a small effect on a slot antenna's radiation performance, which suggests that slot antennas are a superior candidate for mobile terminals compared to microstrip patch antennas.

Internal monopole antenna integrated with a shielding metal case for UMTS mobile devices

An integration design of an internal monopole antenna and an RF shielding metal case for application in UMTS mobile devices is proposed. The monopole antenna is a low-profile (only 3.5-mm) T-shape strip monopole placed above and integrated (through short-circuiting) to the shielding metal case, which is flush with the top edge of the system ground plane of the mobile device. With the integrated shielding case, which provides a coupling-free region for the nearby components such as the RF module, RF circuitry, and battery in the mobile device, possible coupling between the monopole antenna and the nearby components can be avoided. The proposed integration design can thus lead to no degrading effects on the performances of the internal monopole antenna employed in the mobile device. © 2005 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 162–165, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21293

Investigation of Wide-Band Microstrip Slot Antenna

This paper presents the simulation and experimental investigations of a printed microstrip slot antenna. It is a quarter wavelength monopole slot cut in the finite ground plane edge, and fed electromagnetically by a microstrip transmission line. It provides a wide impedance bandwidth adjustable by variation of its parameters, such as the relative permittivity and thickness of the substrate, width, and location of the slot in the ground plane, and feed and ground plane dimensions. The ground plane is small, 50 mm/spl times/80 mm, and is about the size of a typical PC wireless card. At the center frequency of 3.00 GHz, its width of 50 mm is about /spl lambda//2 and influences the slot impedance and bandwidth significantly. An impedance bandwidth (S/sub 11/=-10 dB) of up to about 60% is achieved by individually optimizing its parameters. The simulation results are confirmed experimentally. A dual complementary slot antenna configuration is also investigated for the polarization diversity.

Quad‐band internal monopole mobile‐phone antenna

AbstractA novel internal monopole antenna suitable for applications in AMPS/GSM/DCS/PCS quad‐band mobile phones is presented. The antenna comprises two orthogonal wideband monopole elements for operation at about 900 and 1850 MHz, covering the APMS/GSM (824–894/890–960 MHz) and DCS/PCS (1710–1880/1850–1990 MHz) bands, respectively. The quad‐band monopole antenna is also arranged in a compact structure such that it has a low profile (only 6 mm in this study) and protrudes from the top edge of the system ground plane of a communications device, thus making it very promising as an internal antenna, built‐in within the device's casing. © 2004 Wiley Periodicals, Inc. Microwave Opt Technol Lett 40: 359–361, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.11381

Modelling of a microstrip antenna on a finite ground plane using the expansion wave concept and the aperture integral equation formulation

A microstrip antenna located on a finite ground plane has been analysed. The calculation is split into several steps. In the first step, the microstrip antenna on an infinite ground plane is analysed using the moment method. In the next step, the radiation pattern is calculated using ray tracing techniques. The fields in the layered structure are expanded into a finite number of expansion waves. The expansion waves propagate up to the edges of the finite ground plane, where they diffract. Diffraction coefficients for these waves are calculated using a formulation based on the aperture integral equation. The experimental results are in good agreement with the proposed model.

Coupling of vias in electronic packaging and printed circuit board structures with finite ground plane

A full wave method is presented for modeling and analyzing multiple interactions among vertical vias in densely packaged integrated circuits and printed circuit board with ground plane of finite extent. In such structures, the TEM mode in the planar structure is excited and can propagate and cause interaction of waves among vias. Reflections will also occur at the edges of the finite ground plane. The electromagnetic analysis methodology is an extension of the previous methodology in analyzing multiple scattering among vias for infinite ground plane . The analysis is based upon the cylindrical wave mode expansion of the magnetic field Green's function, the Foldy-Lax multiple scattering formalism and utilizing the resonator modes of a circular cavity. The circular resonator modes are transformed into cylindrical waves onto the cylindrical via structures. Numerical results illustrate the physics of the underlying resonance scattering problems. We consider the cases of a) two coupled active vias of differential mode and b) two coupled vias of common mode. Results are also illustrated for ground plane resonance and the effects of shorting vias on such resonance. The effects of off-centering and the presence of idle vias are also illustrated.

Fabrication technique of ground-plane embedded in a PrBa 2Cu 3O x film

We tried to fabricate planarized patterned ground-plane (GP) structures by using a mechanical polishing technology. Our planarized patterned GPs had the geometry of GP embedded in a PrBa 2Cu 3O x (PBCO) isolation film. This GP structures had no steps on the GP edges and the substrate surface was perfectly covered with PBCO or GP. It was confirmed that the morphology of insulating films on the planarized patterned-GP was uniform over the entire sample surface. The isolation resistance between the electrode layer and the GP was found high (>10 3 Ω cm 2). Furthermore, the high critical current density (>10 6 A/cm 2) of the superconducting striplines did not deteriorate on a planarized patterned-GP. It was thus demonstrated that high-quality uniform multilayer structures can be obtained this new planarized patterned GP.

Improving radiation-pattern distortion of a patch antenna having a finite ground plane

This paper presents a very useful and yet simple method of improving the radiation-pattern distortion of a patch antenna having a finite ground plane. The improvement can be achieved by cutting out the edges of the finite ground plane. This produces a phase shift between the induced equivalent magnetic currents on the edges, thereby causing cancellation in the diffracted fields. We numerically and experimentally examined the effects for some typical patch antennas and confirmed that the ripples in the copolar E plane pattern could be eliminated by using this approach.

Ground plane edge serrations for improved performance of microstrip active reflectarray elements

The paper investigates the effects of ground plane edge serrations on microstrip patch antennas for use in active-element reflectarray applications. Improvements in isolation between the ports of the antenna by this ground plane edge treatment are studied once the microstrip patch geometry has been modified to incorporate the active device. This treatment not only improves the general characteristics of the radiating element, but can also act to stabilize the output and reduce uncontrolled oscillations and other undesired behaviors.

Ground plane edge serrations for improved performance of microstrip active reflectarray elements

The paper investigates the effects of ground plane edge serrations on microstrip patch antennas for use in active-element reflectarray applications. Improvements in isolation between the ports of the antenna by this ground plane edge treatment are studied once the microstrip patch geometry has been modified to incorporate the active device. This treatment not only improves the general characteristics of the radiating element, but can also act to stabilize the output and reduce uncontrolled oscillations and other undesired behaviors.

Shorted, folded planar monopole antenna for dual-band mobile phone

A novel shorted, folded planar monopole antenna for application in GSM/DCS dual-band mobile phones is proposed. The antenna is easily fabricated from stamping a single metal plate, which is then folded onto a foam base of compact size 5×10×40 mm3. In addition, the proposed antenna shows a very low profile of 5 mm protruded from the top edge of the system ground plane, making it very promising to be employed within the casing of a mobile phone as an internal antenna.