Ultra-wideband Microstrip Filter Research Articles

Ultra-Wideband Microstrip Filter Design with Super-Shaped Defected Ground Structures

Ultra-wideband (UWB) microstrip filter design has been proposed by applying defected ground conductor structures designed with the superformula approach. Simultaneously, the effects of the materials used in the designs on the filter properties have been examined. After the filter characteristics have been determined, the filter design has carried out in the AWR program. The filter structure has based on an 8 GHz center frequency fifth-order Chebyshev ultra-wide bandpass filter. The filter model designed in AWR has transferred to the HFSS program, and the effect of FR4 and RO3035 materials on filter characteristics have been investigated. The various number of defects, each shaped with superformula, is opened to the base conductor, and their effects are observed. The parameters in the superformula proposed by Johan Gielis have been calculated in the MATLAB program. PCB productions of the designed filters have been made, and experimental measurements have been taken with the Anritsu spectrum analyzer device. When the results obtained from electromagnetic simulation programs have compared with the experimental measurement results of the filters produced, it has been seen that the results are consistent with each other.

Compact multi‐mode UWB microstrip filter using meander resonator

ABSTRACTIn this paper, traditional microstrip resonator is meandered to construct a compact multi‐mode resonator (MMR). The meander resonator is very simple but convenient for ultra‐wide band (UWB) passband filter. And then, a UWB microstrip filter with six transmission poles in the passband is achieved by using only two resonators. The filter has an amplitude frequency response with a passband from 1.8 GHz to 4.7 GHz, the simulated return loss in passband is better than −20dB, and the measured one is better than −19dB. The tested insertion loss at center frequency is about 0.38 dB. Methods of adjusting the bandwidth of this new kind of UWB filter is also discussed in this paper. © 2016 Wiley Periodicals, Inc. Microwave Opt Technol Lett 58:2026–2029, 2016

Switchable square ring bandpass to bandstop filter for ultra-wideband applications

In this manuscript, serial-shunt of square ring resonators with step-impedance open circuited stub resonators to produce a new on-off switchable bandpass to bandstop response in the same ultra-wideband microstrip filter structure is proposed. The closed ring of series-shunt square ring resonators with a combine stubs are introduced to excite the bandpass response while bandstop characteristic excited when gaps are embedded in the corners of the square ring resonators. The main advantage of this microstrip filter is its capability to switch from bandpass-to-bandstop operation using open-short gap, respectively. A microwave simulator is utilized to show the switchable case by replacing Skyworks radio frequency diodes (RF-PIN) instead of those gaps. The entire filter models have been simulated using the computer simulation technology (CST) Microwave Studio. The computed results for the proposed filters were compared with the measured results of the both prototype structures (bandpass- and bandstop-filter). The codes also showed good agreement between them. Other advantages include being small in size, and low in effective cost.

Open and Short Ended Stubs UWB Microstrip Bandpass Filter

In this paper an ultra-wideband (UWB) microstrip filter is designed and tested. The filter has a passband from 0.99 to 10.7 GHz with a maximum insertion loss of -1.13dB at 1.9GHz, and a wide stopband up to more than 10GHz with a rejection mostly better than 10dB. This UWB microstrip filter design is based on using both open and short ended stubs. The design steps, simulated and experimental results of the designed UWB microstrip filter are presented.

“Via-Less” UWB Filter Using Patched Microstrip Stubs

This paper presents an Ultra-Wide Band (UWB) microstrip filter which is initially modeled from a quarter-wavelength short-circuited stubs, without the use of any vias. All vias that provide short circuit stubs are replaced by microstrip patches which have low impedance at high frequency. The purposes of substituting the vias are to simplify the fabrication process and reduce losses due to capacitive effects of vias. The microstrip patch impedance is determined by calculation and simulation in such a way that optimum S-parameters and frequency responses are obtained. The measured S-parameters have shown encouraging results of –3 dB cut-off frequencies from 3.58 GHz to 10.57 GHz with minimum magnitude of insertion loss better than 1 dB and return loss of better than –16.9 dB in the passband. The final dimension of “via-less” UWB microstrip filter is measured at 41.0 × 15.1 mm2.

Design of sharp-rejection and low-loss wide-band planar filters using signal-interference techniques

A new class of sharp-rejection, low insertion-loss wide-band planar filters is presented in this letter. The proposed filter topology uses transversal signal-interference filtering sections made up of two transmission-line segments connected in parallel. Thus, under signal-interaction principles, the filtering action comes about through the generation of multiple out-of-band power transmission zeros and constructive in-passband signal combinations. Design equations and guidelines to adjust both the bandwidth and the out-of-band performance of the filtering response through the design parameters of the transversal section are also provided. Furthermore, the theoretical results are validated with the manufacture and characterization of an ultra-wideband microstrip filter prototype at 5 GHz.

UWB microstrip filter design using a time-domain technique

A time-domain technique is proposed for ultra-wideband (UWB) microstrip-filter design. The design technique uses the reflection coefficient (S11) specified in the frequency domain. When the frequency response of the UWB filter is given, the response will be approximated by a series of UWB pulses in the time domain. The UWB pulses are Gaussian pulses of the same bandwidth with different time delays. The method tries to duplicate the reflection scenario in the time domain for very narrow Gaussian pulses (to obtain the impulse response of the system) when the pulses are passed through the filter, and obtains the value of the filter coefficients based on the number of UWB pulses, amplitudes, and delays of the pulses. © 2005 Wiley Periodicals, Inc. Microwave Opt Technol Lett 47: 387–391, 2005; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21177