Broadband Microstrip Research Articles

Thin film, thick film microstrip band pass filter: a comparison and effect of bulk overlay

This paper reports the comparison of two fabrication techniques (viz. thin and thick film) for microstrip broadband filter in the X-band. The effect of bulk Al 2O 3 overlay (in pellet form and at different positions) on the characteristics of the broadband filter is also reported in this paper. The characteristics vary with the overlay position and thin film circuits seem to be more affected than thick film circuits.

A procedure to design aperture‐coupled stacked‐microstrip antenna based on experiment

AbstractThe aperture‐coupled stacked‐microstrip antenna (ACSMA) is an important type of broadband microstrip antenna. A simple and practical procedure for its design is presented in this letter. Utilizing the technique, one ACSMA of L‐band has been designed. The experiments have been carried out and the measurement results verified the applicability of the method. © 2002 Wiley Periodicals, Inc. Microwave Opt Technol Lett 35: 244–247, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.10569

Design of broadband microstrip series array for mm-wave applications

A simple strategy is presented for the design of broadband microstrip series arrays at millimetric wavelengths. The array performance is enhanced systematically by cascading several microstrip patch elements in a series configuration and terminated in a matched load. Experimental and computed full-wave results indicate good agreement, showing that a bandwidth in excess of 11% is achievable.

Broadband microstrip antenna excited by coplanar waveguide

AbstractThe configuration and radiation characteristics of an antenna system exciting a rectangular microstrip antenna with coplanar waveguide are studied. In addition, a method for broadbanding is discussed. (1) The radiation characteristics of this antenna are characterized by simulation and experiment, and basic design data are obtained. (2) A method of construction for an antenna system with a parasitic element stacked on the microstrip antenna is investigated. It is confirmed that a broadband characteristic of about 23% in terms of return loss (VSWR ≤ 2.0) can be obtained. (3) In addition, the radiation pattern and gain of the present antenna system are studied. It is shown that these characteristics are broadband in nature. Further, the mutual coupling between the elements is studied, since this is important for the consideration of array antenna. Basic design data are obtained. © 2002 Wiley Periodicals, Inc. Electron Comm Jpn Pt 1, 85(10): 1–7, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecja.10010

Broad-band dual-polarized single microstrip patch antenna with high isolation and low cross polarization

This paper presents a new design of a broad-band dual-polarized single microstrip patch antenna with highly decoupled input ports and low cross-polarization (XP) radiation. A prototype of the proposed antenna with center frequency at 1800 MHz is presented. Both the dual linear polarizations have 10-dB return-loss impedance bandwidths greater than 14% and high decoupling between the two input ports (S/sub 21/ less than -40 dB across the entire bandwidths) is obtained. Moreover, the XP radiation in the principal planes of the dual linear polarizations is seen to be less than -20 dB.

A broadband and thin circular microstrip antenna suitable for 1800 MHz band operation

AbstractA novel broadband design of a thin circular microstrip antenna suitable for 1800 MHz band operation is demonstrated. Due to the embedding of reactive loading and slots in the ground plane, a broadband operation with its two resonant modes centered at about 1800 MHz has been obtained. The proposed broadband design shows that an antenna bandwidth is ∼4.9 times that of a conventional circular microstrip antenna. Details of the antenna design and experimental results of the proposed antenna are presented. © 2002 Wiley Periodicals, Inc. Microwave Opt Technol Lett 32: 434–435, 2002.

Broadband and compact multi-pole microstrip bandpass filters using ground plane aperture technique

A gound plane aperture technique is developed for effective enhancement of the capacitive coupling factor in the parallel-coupled microstrip line (PCML). By applying a so-called ‘short-open calibration’ (SOC) scheme in the fullwave method of moments (MoM) algorithm, this PCML with two external lines is characterised by an equivalent J-inverter network with its susceptance and two electrical line lengths. Extracted parameters indicate that the coupling factor appears to be frequency-dependent and its maximum value rises rapidly as the aperture is widened. With the introduction of a single microstrip line section between two identical PCMLs, a broadband and compact multi-pole microstrip bandpass filter is proposed for the first time, and its electrical behaviour is studied and optimised on the basis of its equivalent circuit network. The network-based optimised results are confirmed by an EM simulation of the entire filter layout, featuring ultra-broadband and four-pole bandpass behaviour. Further, a single capacitively loaded line section is utilised to formulate a multi-pole bandpass filter, and its electrical effects are also discussed for filter design. The predicted and measured results confirm attractive properties of the proposed multi-pole filter with BW=60%. ∣S11∣<−16dB and 220% wide upper stop-band.

A broadband and compact microstrip antenna for IMT‐2000, DECT, and bluetooth integrated handsets

AbstractA novel and broadband semidisk microstrip antenna suitable for a portable and compact terminal integrated with the 3G IMT‐2000 cellular system, DECT mobile system, and Bluetooth wireless technology is discussed both theoretically and experimentally. Using both bandwidth‐enhancement and size‐miniaturization methods, a broad impedance bandwidth (return loss ≤−10 dB) of 32.4% from 1.86 to 2.58 GHz is obtained. Typical characteristics of the proposed antenna are addressed and discussed. Good agreements are obtained in the measured and simulated results. © 2002 John Wiley & Sons, Inc. Microwave Opt Technol Lett 32: 204–207, 2002.

A systematic method to design single‐patch broadband microstrip patch antennas

AbstractA simple electrical network for a single‐layer microstrip patch antenna (SLMPA) and the feeding structure (coaxial probe and compensating capacitor) is proposed to predict the input impedance. The mathematical analysis allows us to design an optimum feed that enhances the impedance bandwidth (BW). © 2001 John Wiley & Sons, Inc. Microwave Opt Technol Lett 31: 185–188, 2001.

Via-free broadband microstrip to CPW transition

A broadband microstrip to coplanar waveguide (CPW) transition is proposed. The design is based on vertical resonant coupling between the microstrip and CPW. The transition does not require via holes, wire bonds, or air bridges. The design of the transitions on C band shows good agreement with return loss better than –15 dB over 2.8–7.5 GHz. The new transition has the advantages of broad bandwidth and easy fabrication.

Single-layer miniature broadband microstrip antenna using wirebonding technique

A wirebonding technique is presented for designing a single-layer miniature and broadband microstrip antenna on the basis of experiments. The technique most commonly applied in device assembly will support manufacturing and packaging of small antennas by avoiding via-holes. Consisting of three short-circuited elements fed by a parasitic wirebonding configuration, the antenna in a package format has the merits of wide impedance bandwidth, miniature structure, flexible matching and easy integration into RF front-end units. Its stable and broadside copolarised radiation patterns in the frequency range of 2.40-2.51 GHz are satisfactory for Bluetooth application.

Versatile Semi-Disc Microstrip Antennas: Study and Application

This paper investigates a novel shorted semi-disc microstrip antenna, its variation and potential application. By employing both bandwidth enhancement method and size miniaturisation technique, it is highly possible to have a compact radiating element with broadband, single-frequency or multi-frequency behaviour. These properties are presented in detail in the paper. Typical design of a small and broadband microstrip antenna suitable for IMT-2000 mobile handsets introducing two similar semi-disc patches is highlighted. A total of four microstrip antennas have been proposed and discussed both theoretically and experimentally. Measured characteristics of the proposed antennas, such as input impedance and far-field radiation patterns, are in good agreement with simulated results.

Broadband patch antenna forE-band applications

A broadband microstrip patch antenna fed by slot coupling is described. The operation frequencies are in the E-band, and the required bandwidth is about 2 GHz. Results obtained from an antenna design to operate from 40.5 to 42.5 GHz are presented. © 2001 John Wiley & Sons, Inc. Microwave Opt Technol Lett 29: 40–42, 2001.

A novel E‐shaped broadband microstrip patch antenna

A novel coaxial-fed E-shaped microstrip patch antenna is proposed in this paper. The proposed antenna is found to have a much broader impedance bandwidth as compared to the conventional U-slot antenna. An impedance bandwidth of about 33.8% is achieved for the proposed E-plane antenna. Through the use of a washer on the proposed antenna, the probe inductor is compensated, and an impedance bandwidth of 40% is thus obtained. The E-plane radiation pattern for both the proposed antenna and the one incorporated with the washer remains relatively constant through the band. A comparison between the U-slot antenna and our proposed antennas is made in the paper. © 2000 John Wiley & Sons, Inc. Microwave Opt Technol Lett 27: 348–352, 2000.

Broad-band cavity-backed and capacitively probe-fed microstrip patch arrays

A hybrid full wave method for the analysis of probe-fed infinite phased arrays of single and stacked microstrip patches, backed by metallic cavities, is applied to investigate the combined utilization of the capacitive probe-feeding technique and the cavity enclosure of microstrip patches. The goal is to obtain broad-band microstrip antennas on thick substrates without the limitations due to the generation of surface waves of the conventional microstrip antennas on infinite substrates. A design procedure for the capacitive coupling is investigated and theoretical results for the active input impedance and radiation characteristics of different wide-band antenna designs are presented.

Broadband microstrip patch antennas for MMICs

A broadband microstrip patch antenna well suited for monolithic microwave integrated circuits (MMICs) is presented. The antenna exhibits a measured bandwidth of 35%, low surface wave loss, a high front-to-back ratio, and is fabricated directly on the MMIC substrate material. The predicted and measured input impedances are given along with the measured radiation performance.

Broadband microstrip to dielectric image line transitions

Novel broadband microstrip to dielectric image line (DIL) transitions have been developed. A conducting strip is flared linearly from the microstrip line to the DIL. The DIL and microstrip substrate are on the same side of their common ground plane. Theoretical simulation results, obtained by using the finite-difference time-domain method, agree well with experimental results. The transitions should have applications in the integration of the dielectric image line with microwave integrated circuits (MICs) and monolithic microwave integrated circuits (MMICs).

A novel E-shaped broadband microstrip patch antenna

A novel coaxial-fed E-shaped microstrip patch antenna is proposed in this paper. The proposed antenna is found to have a much broader impedance bandwidth as compared to the conventional U-slot antenna. An impedance bandwidth of about 33.8% is achieved for the proposed E-plane antenna. Through the use of a washer on the proposed antenna, the probe inductor is compensated, and an impedance bandwidth of 40% is thus obtained. The E-plane radiation pattern for both the proposed antenna and the one incorporated with the washer remains relatively constant through the band. A comparison between the U-slot antenna and our proposed antennas is made in the paper. © 2000 John Wiley & Sons, Inc. Microwave Opt Technol Lett 27: 348–352, 2000.

Broadband microstrip antenna with directly coupled and parasitic patches

A new design of a rectangular microstrip antenna with a directly coupled patch and two gap-coupled parasitic patches for achieving broadband operation is proposed and experimentally studied. The proposed broadband antenna has a compact configuration such that the required realty space for implementing the antenna is minimized. Experimental results show that the proposed antenna can have an antenna bandwidth greater than six times that of a single rectangular microstrip antenna. Details of the proposed antenna are described, and experimental results of the broadband performance are presented and discussed. ©1999 John Wiley & Sons, Inc. Microwave Opt Technol Lett 22: 348–349, 1999.

A method for designing broad-band microstrip antennas in multilayered planar structures

The narrow bandwidth of a microstrip antenna is one of the important features that restrict its wide usage. A simple and practical method for the design of broad-band microstrip antennas is presented in this paper. Utilizing this design technique, several two-layer microstrip antennas have been proposed. To confirm the applicability of the method for the designs of antennas at L-band, experiments have been carried out. The measured results show that the proposed antennas have a bandwidth of up to 25.7%. Also, the method proposed in this paper is applicable to the design of other types of multilayered planar antennas.