Broadband Microstrip Research Articles

Investigation on broadband microstrip two element monopole antenna with high gain

AbstractThe paper deals with the theoretical and experimental investigation on a simple two-element antenna exhibiting wideband operation. This antenna consists of two monopole antenna elements with modified ground plane. Generally, monopole antenna provides low gain. Here, upto 6 dBi gain has been achieved. Percentage bandwidth of the antenna is 80%. Previously, researchers have already achieved this type of percentage bandwidth but in most of the cases, gain is much lower. The novelty of this paper lies in the achievement of wide bandwidth with high gain.

QUASI-ELLIPTIC MICROSTRIP BANDSTOP FILTER USING TAP COUPLED OPEN-LOOP RESONATORS

In this paper, we will present a quasi-elliptic bandstop filter using asynchronously tuned resonators. To demonstrate this technique, a novel broadband microstrip bandstop filter is also proposed using distributed resonators. To achieve wide bandwidth using distributed resonators, strong couplings are required. This is achieved using tap coupled to avoid very narrow gaps which are costly to manufacture. The filter exhibits a factional bandwidth of approximately 35%. A simple practical transformation technique for transforming Chebyshev bandstop filter to asynchronously tuned quasi-elliptic bandstop filter will be presented.

A NEW BROADBAND MICROSTRIP QUADRATURE HYBRID WITH VERY FLAT PHASE RESPONSE

A new broadband microstrip branch-line quadrature hybrid with very flat phase response is presented. The device is made by cascading four branch-line couplers with arbitrary power division. The novel design is based on the microstrip transposition of a broadband waveguide polariser [4]. Across a 32% bandwidth centred at 9.3 GHz, the RL and the IL are respectively -15 dB and -3 dB/-4 dB; the phase difference is very flat, i.e. 90°±1.5°.

A Compact and Broadband Microstrip Stacked Patch Antenna With Circular Polarization for 2.45-GHz Mobile RFID Reader

A compact and broadband microstrip stacked patch antenna with circular polarization (CP) for a mobile 2.45-GHz passive radio frequency identification (RFID) reader is presented. The proposed antenna consists of two stacked patches fed with an S-shaped impedance-matching network (IMN), which is connected by a probe. With the proposed S-shaped IMN feed technique, a good impedance matching and symmetrical broadside radiation patterns could be obtained. The CP operation could be attained simply by the upper parasitic patch rotating 90 <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex Notation="TeX">$^{\circ}$</tex></formula> sequentially based on the lower patch and truncating corners. Additionally, with four symmetric-L narrow slots on the patches, the compact operation could be obtained. The proposed reader antenna matching is optimized by regulating the sizes of the S-shaped IMN: <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex Notation="TeX">$S_{\rm x}$</tex> </formula> and <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex Notation="TeX">$S_{\rm y}$</tex> </formula> . Experimental results show that the reader antenna of size 58 <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex Notation="TeX">$\, \times \,$</tex></formula> 58 <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex Notation="TeX">$\, \times \,$</tex></formula> 11 mm <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex Notation="TeX">$^3$</tex></formula> has a 3-dB beamwidth of more than 91 <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex Notation="TeX">$^{\circ}$</tex> </formula> . The peak gain is optimized in the frequency range from 2.31 to 2.56 GHz of larger than 6 dBi, and it achieves 6.32 dBi in the center frequency 2.45 GHz. The voltage standing wave ratio (VSWR) <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex Notation="TeX">${&lt;}2$</tex></formula> impedance bandwidth is larger than 15.1%.

Compact Ultra Wide Band Microstrip Bandpass Filter Based on Multiple-Mode Resonator and Modified Complementary Split Ring Resonator

A new class of broadband microstrip filters for Ultra Wide Band (UWB) applications is proposed. In the design, different stages of parallel-coupled microstrip line and other stages with a Modified Complementary Split Ring Resonator (MCSRR)—a concept proposed here for the first time—are adjusted to obtain the desired response with broadband, sharp rejection, low insertion loss, and low return loss. Full wave simulation results as well as measurement results from fabricated prototypes are presented, showing good agreement. The proposed technique offers a new alternative to implement low-cost high-performance filter devices, applicable to a wide range of communication systems.

Broadband Multilayered Array Antenna with EBG Reflector

Most broadband microstrip antennae are implemented in the form of slot structure or laminate structure. The impedance bandwidth is broadened, but meanwhile, the sidelobe of the directivity pattern and backlobe level are enlarged. A broadband stacked slot coupling microstrip antenna array with EBG structure reflector is proposed. Test results indicate that the proposed reflector structure can effectively improve the directivity pattern of stacked antenna and aperture coupled antenna, promote the front-to-back ratio, and reduce the thickness of the antenna. Therefore, it is more suitable to be applied as an airborne antenna.

Review and Survey of Broadband Microstrip Patch Antennas

Microstrip Patch Antenna (MPA) is generally used in modern communication devices, and a large part of day-to-day communication is done through it. Study of literature of past few year shows that, the leading work on MPA is focused on designing compact sized broadband microstrip antenna. But inherently MPA have narrow bandwidth so to enhance bandwidth various techniques are engaged. This review paper demonstrates some commonly engaged techniques to fabricate MPA with broader-bandwidth since last few decades.

Broadband dual-band stacked square microstrip antenna with shorting plates and slits

A stacked microstrip antenna with shorting plates and slits is proposed as a broadband dual-band antenna. By shorting the upper patch to the lower patch at two apexes of the diagonal of the square patch, the bandwidths (for VSWR ≤2) at the two frequency bands are enhanced and the absolute gain at the high-elevation angles at the higher-frequency band is improved. Moreover, the cross polarisation in H plane at the higher-frequency band is reduced by inserting the slits on the lower patch conductor. The proposed antenna radiates to the high-elevation angles at the two frequency bands. The measured bandwidths (for VSWR ≤2) with an absolute gain at thetas=0°≥4 dBi are 19.1 and 18.7% at the lower and higher-frequency bands, respectively.

Compact broadband microstrip rat-race couplers using microstrip/slotline phase inverters for arbitrary power-dividing ratios

Compact broadband microstrip rat-race couplers using microstrip/slotline phase inverters are proposed. A wide range of power-dividing ratio () is achieved by varying the impedance ratio of the transmission lines, while the dual-band impedance matching characteristic with frequency ratio () is obtained by varying the impedances of the transmission lines only. For verification, a rat-race coupler with power-dividing ratio of and operating at 1.0/2.5 GHz is designed, fabricated, and measured. The measured results are in good agreement with the simulated ones. The measured results show a bandwidth of 120% with better than 10-dB return loss and 31-dB isolation from 0.69 to 2.74 GHz.

Compact and Wide Upper-Stopband Triple-Mode Broadband Microstrip BPF

A broadband microstrip bandpass filter (BPF) with compact size, sharp skirt and wide upper-stopband performance is proposed using the triple-mode stub-loaded resonator. The resonator can generate one odd mode and two even modes in the desired passband. Due to the main path signal counteraction, two transmission zeros T z1 , T z2 can be created near the passband edge to achieve sharp skirt. Two transmission zeros T z4 , T z5 are created between two harmonic frequencies h m2 , h m3 by the folded open stub and the interdigital coupling feeding lines, respectively. Owing to the source-load coupling, one zero T z3 is introduced to deepen the stopband. Meanwhile, the zero T z1 is shifted to the lower cut-off frequency and the other three ones T z2 , T z4 , T z5 can be slightly turned to suppress three harmonic frequencies h m1 , h m2 , h m3 . O ne filter prototype with the fractional bandwidth 34% is designed , fabricated and measured .

Compact and Wide Upper-Stopband Triple-Mode Broadband Microstrip BPF

A broadband microstrip bandpass filter (BPF) with compact size, sharp skirt and wide upper-stopband performance is proposed using the triple-mode stub-loaded resonator. The resonator can generate one odd mode and two even modes in the desired passband. Due to the main path signal counteraction, two transmission zeros T z1 , T z2 can be created near the passband edge to achieve sharp skirt. Two transmission zeros T z4 , T z5 are created between two harmonic frequencies h m2 , h m3 by the folded open stub and the interdigital coupling feeding lines, respectively. Owing to the source-load coupling, one zero T z3 is introduced to deepen the stopband. Meanwhile, the zero T z1 is shifted to the lower cut-off frequency and the other three ones T z2 , T z4 , T z5 can be slightly turned to suppress three harmonic frequencies h m1 , h m2 , h m3 . O ne filter prototype with the fractional bandwidth 34% is designed , fabricated and measured .

Design of a MEMS Broadband Microstrip Patch Antenna Based on Minkowski Fractal Boundary

A MEMS broadband microstrip patch antenna based on Minkowski fractal boundary is designed. An air layer is designed in the antenna’s high resistance silicon substrate by MEMS technology and microstrip patch antenna with second degree iteration Minkowski fractal boundary is simulated. Then different p on the influence on the broadband performance of the antenna is discussed. The simulation results show that the broadband performance can be gained from microstrip patch antenna with MEMS air layer based on second iteration Minkowski fractal boundary. 23.34% relative bandwidth of the optimized antenna is achieved and the requirement of the broadband communication is satisfied.

Ka Band Novel Concise Sine Substrate Integrated Waveguide Bandpass Filter

A novel concise sine substrate integrated waveguide (SSIW), with both sides metallized via holes periodic undulation, is firstly proposed for developing bandpass filter (BPF) at millimeter frequency range. It has advantages of remarkable simplicity, compact size and low insertion loss. Simultaneously, a broadband microstrip to SSIW transition is proposed. Transition experimental results show less than 2 dB insertion loss at nearly whole Ka passband. Then, several Ka band SSIW BPFs with different passband widths and center frequencies are designed and fabricated. The experimental results demonstrated that the SSIW BPF passband width and center frequency could be designed by using different undulate amplitudes and periods of the SSIW.

Aperture-coupled multi-layer broadband ring-patch antenna array

An aperture-coupled multi-layer broadband microstrip array antenna with coupling ring slots and modified ring patches is presented. The structure of the array consists of a 3-dB 180°-phase shifter, two 1-port's and two 2-port's aperture-coupled microstrip antennas. All parts of the array antenna are designed for broadband operation. The array antenna works based on the back coupling to the microstrip line of 2-port aperture-coupled antenna. Simulation results of the array display encouraging properties, such as wide impedance bandwidth of 77% for |S11| < -10dB and nearly stable gain. The maximum gain of the array antenna is almost 12.65dBi at 5GHz. The radiation efficiency, radiation pattern, side-lobe level and cross-polarization are also adequate within the impedance bandwidth between of 3.34 and 7.53GHz.

Broadband Millimeter-Wave Microstrip Comb-Line Antenna Using Corporate Feeding System with Center-Connecting

A broadband microstrip comb-line antenna using a corporate feeding system was developed. The antenna was composed of four colinearly-arranged comb-line antennas with traveling-wave excitation fed by a parallel-feeding circuit of tournament configuration. The total phase deviation due to frequency change became one fourth of the ordinary series feeding from the end of the antenna. Furthermore, the terminations of the inner two comb-lines were connected at the overall center of the developed antenna. Therefore, the narrowband matching elements are not necessary and the amplitude deviation of the aperture distribution for input from one side due to frequency change is compensated by deviation for input from the other side. Broad bandwidth can be expected by using the proposed configuration. The proposed antenna was designed at 76.5GHz. The effect of the proposed feeding-circuit for broadband operation was confirmed by comparing the measured performances of the antennas fed by other feeding circuits; the end feeding, the center feeding and the ordinary corporate feeding. The bandwidth of the proposed corporate feeding antenna with the center connecting was approximately 14% and 7% wider than the antennas of the center feeding and of the ordinary corporate feeding, respectively.

An Approach Based on Finite Element Method for CAD of Printed Antennas

A novel computer-aided design (CAD) procedure for microstrip antennas is proposed in this letter. It is based on a previously developed analysis methodology that combines the finite element method (FEM), domain decomposition, and a technique called multipurpose admittance matrix. This method is reformulated in order to allow continuous geometry variations of conducting surfaces, making a 2D-FEM optimization process possible. Measured and numerical results for a practical broadband microstrip antenna design demonstrate its robustness and versatility.

High Selectivity Broadband Bandpass Filter Using Stub-Loaded Quadruple-Mode Resonator

—In this paper, a compact and high selectivity broadband microstrip bandpass filter (BPF) using stub-loaded resonator is proposed. The basic block of the proposed filter is a quadruple-mode resonator consisting of a stepped-impedance resonator and three shunt open stubs. The proposed resonator can provide two even-mode, two odd-mode frequencies and two transmission zeros. The even-mode resonant frequencies can be flexibly controlled by the centre stub, while the odd-mode frequencies are fixed. The two other symmetrical stubs can both affect even- and odd- mode frequencies. The proposed filter exhibits high selectivity profiting from the two transmission zeros (TZs) near the passband created by two types of stubs. The measured –3 dB bandwidth is 1.0 GHz at the centre frequency of 2.5 GHz, and the S 21 exhibits a wide spurious free response up to 6 GHz. Measured results show good agreements with EM simulation results.

Broadband and size-reduced microstrip antenna with double T-feed for UHF RFID tags

A novel radio frequency identification tag antenna at 915 MHz using a bent meandered strip, a U-microstrip patch and an adjustable double T-feed is proposed, which is suitable for attaching to dry objects with various content. The antenna's size is 21.2 × 63.0 mm2. The antenna achieves 400 MHz bandwidths, 1.60 dBi gains, and a good radiation pattern. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett 53:2697–2699, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26332

Compact coupled line broadband microstrip to slotline transition

A compact broadband microstrip to slotline transition is designed and experimentally studied. An elliptical tapered profile and patches are used to minimise the discontinuity effect of field variation from microstrip to slotline within a short range. A prototype of the back-to-back version transition is also fabricated. Measured results validate the design concept.

Design of Multilayer Substrates Microstrip Patch Antenna for Fuze Application

A broadband microstrip patch antenna with multi-layer substrate for fuze application is designed. The multi-layer substrate is composed of the bottom layer of Si with low electric conductivity, the middle and the top layers of Si with high electric conductivity. An air cavity is fabricated by inductively coupled plasma (ICP) etching in the middle layer of Si to reduce the effective dielectric constant of the multi-layer substrate. The multi-layer substrate microstrip patch antenna is simulated and optimized by finite element method. The simulation results show that operating at 10GHz, the bandwidth and the gain of the multi-layer substrate microstrip patch antenna are 15.5% and 6.1dB respectively, which meet the needs of the application in fuze well.