Enhanced Design Of Electronically Reconfigurable Integrated Microwave Filter And Antenna For Wireless Communication Systems

The reconfigurable integrated filter and antenna is one of the major interest for researchers due to the potential significant advantages compare to the typical standard integrated structure. The growth in reconfigurable integrating technology is not limited to a single tunable parameter such as operating frequency, bandwidth and attenuation but it can be combination parameters depending on the applications. There are many techniques have been developed to achieve adaptable reconfigurable integrated filter and antenna but majorities of the reconfigurable designs are focused on a single element either on an antenna or the filter. Thus, it limits the tunable range and flexibility response of the reconfigurable design will be a challenging task. On the other hand, developing a Ultra-Wideband (UWB) antenna is one of the crucial components for UWB communications systems and has been widely studied for many years. Moreover, the reconfigurable UWB designs can be developed the desired filtering antenna which can reject unwanted signal interferences. However, most of these techniques produce excessive band rejection, which leads to reject desired frequencies, thus producing a narrowband notch characteristics is a challenging issue. Therefore, the aim of this research is to design novel structure of reconfigurable integrated technique of planar structure which promises a new potential functionality of the microwave devices. Two designs approach were introduced which is reconfigurable SIW filter and antenna and reconfigurable dual band-notched UWB antenna using FR-4 substrate and Roger Duroid RO4350B with dielectric constant of 4.6 and 3.48 respectively. To realize the concept, reconfigurable SIW filter and reconfigurable patch antenna have been combined using the multilayer technique into a single structure while UWB antenna and reconfigurable notch filter were combined on the same planar. To validate the design technique, the equivalent circuit model of the tunable varactor diode network is presented to study the tunability mechanism. Two commercial software programs that have been used in the design and development of two main designs namely Advanced Design System (ADS) software and CST Studio Suite software. All designs were simulated, manufactured and measured. Reconfigurable integrated SIW filter and antenna provide a good attenuation tuning range about 15.5 dB with improvement up to 55 % and only shifts 1 MHz from the origin centre frequency while reconfigurable UWB antenna with band-notched provide a good range up to 210 MHz. This design has smaller compact size of 37.6 mm x 28.0 mm with bandwidth for peak notch of 224.76 MHz and 89.90 MHz for both notches. The experimental results show a good agreement with the simulated results. The benefits of the reconfigurable integrated design are potentially miniaturizing overall structure, good tuning capability, easy to fabricate and cost effective. The outcomes of the proposed reconfigurable integrated design may facilitate improvements in an integrated technique with a good tuning capability for wireless communication systems

Design of integrated rectangular SIW filter microstrip patch antenna for wireless communications

This thesis presents the design and development of an integrated substrate integrated waveguide (SIW) filter and microstrip patch antenna, which utilizes cascaded and multilayered techniques. Integrated method contributes to the reduction of the overall design size in front-end subsystems as well as in manufacturing cost. The first design process was developed using the basic concept of filter with the characteristics of the circuit transformation of lowpass prototype network for filter, antenna and integrated filter and antenna with the sequence procedure as a starting point. The next process involved the designing of Chebyshev bandpass for filter, antenna and integrated filter and antenna at desired frequency based on single- and dual-mode. The second and third design process were developed using planar structure based on SIW technology and patch antenna. The concept of SIW was formulated from a standard conventional rectangular waveguide by a set of design rules. Meanwhile, microstrip patch antenna was designed based on the procedures and techniques in order to integrate with SIW filter. Integrated method using cascaded and multilayer are developed from the combination between SIW filter and patch antenna. Two commercial software programs that were used in the design and development of integrated SIW filter and antenna bandpass filter namely Advanced Design System (ADS) software, and CST Studio Suite software. All designs were simulated, manufactured and measured. The experimental results showed good agreement with the simulated results. The main benefits of the integrated SIW filter and microstrip patch antenna are the reduction of the overall size, ease to fabricate, low in cost and the use of standard printed circuit board process. This new novel of microwave filters is considered suitable and is an alternative solution for 3G, ISM, WLAN and LTE applications without an addition of external common impedance network on the systems

Design of Reconfigurable Defected Ground Structure (DGS) for UWB Application

This paper presents the design of reconfigurable defected ground structure (DGS) resonator that can be integrated with ultrawide-band (UWB) microwave filter to produce bandpass and bandstop response simultaneously. The reconfigurable DGS is designed based upon coplanar waveguide (CPW) technology to exhibit bandstop characteristic at 3.5 GHz and 5.5 GHz using FR-4 on a 1.6 mm dielectric substrate thick with dielectric constant er = 4.6. The simulation performance shows promising results that could be further validated during the experimental works. This topology of reconfigurable DGS is useful for applications when the undesired signals need to be removed such as in wideband systems

A Compact Reconfigurable Dual Band-Notched Ultra-Wideband Antenna using Varactor Diodes

In this paper, a reconfigurable dual band-notched ultra-wideband (UWB) antenna is presented. The antenna design consists of a circular shape with two pairs of the L-resonator. To realize the notch characteristics in WLAN at 5.2 GHz and 5.8 GHz bands, the half wavelength of the L-resonator is introduced in the design. The T-shaped notch is etched in the ground to enhance the bandwidth which covers the UWB operating frequency range from 3.219 – 10.863 GHz. The proposed reconfigurable dual band-notched UWB antenna shows good impedance matching for the simulated in the physical layout. Furthermore, the proposed antenna has a compact size of 37.6 x 28 mm2. This proposed reconfigurable design can provide an alternative solution for the wireless system in the designing of a band-notched antenna with a good tuning capability

Microwave Planar Sensor for Determination of the Permittivity of Dielectric Material

This paper proposed a single port rectangular microwave resonator sensor. This sensor operates at the resonance frequency of 4GHz. The sensor consists of micro-strip transmission line and applied the enhancement method. The enhancement method is able to improve the return loss of the sensor, respectively. Plus, the proposed sensor is designed and fabricated on Roger 5880 substrate. Based on the results, the percentage of error for the proposed rectangular sensor is 0.2% to 8%. The Q-factor of the sensor is 174

Design of Low-Loss Coaxial Cavity Bandpass Filter with Post-Manufacturing Tuning Capabilities

This paper presents a low-loss of coaxial cavity bandpass filter with post-manufacturing tuning capabilities.A systematic filter development using the lowpass prototype as a starting point to produce 4th degreeChebyshevbandpass response is demonstrated. The coaxial cavity filter based upon TEM mode of propagation has the center frequency of 2.5 GHz and bandwidth of 168MHz. The insertion loss of 0.15 dB insertion loss and return loss better than 15 dB areobtained particularly in the passband. This type of microwave filter would be useful in any microwave systems where the low insertion loss and high selectivity are crucial, such as in a base station, radar and satellite transceivers

Rectangular Microstrip Patch Antenna Based on Resonant Circuit Approach

This paper presents the investigation based upon the resonant circuit approach to characterize the rectangular microstrip patch antenna from the low-pass prototype lumped element. The physical layout of the rectangular microstrip patch antenna based on single-mode and dual-mode will be established. An improvement on bandwidth of the antenna can be achieved by increasing the number of modes. In the paper, the understanding of microwave filter synthesis technique is applied in order to obtain the resonance at 2 GHz. A notch technique is used in the design to produce dual-mode frequencies on the microstrip patch antenna. The prototype circuit and proposed physical layout of the single and dual-mode microstrip patch antennas are demonstrated through the analysis of circuit and EM simulations in order to proof the proposed concept. This study would be useful to realize antenna for broadband applications as well as to investigate the appropriate technique for integrating antenna and microwave filter

A Novel Structure of Multilayer SIW Filter And Patch Antenna

This paper presents the investigation based upon the resonant circuit approach to distinguish in between the microwave filter and antenna from the equivalent circuit to physical layout where this system is used to reduce the overall volume of RF front-end subsystem especially in wireless communication systems. The physical layouts of the Substrate Integrated Waveguide (SIW) filter and microstrip patch antenna based on single-mode is established based on multilayer technique. This study focuses on the integrated rectangular SIW filter with rectangular microstrip patch antenna to produce radiating and filtering system in a single device. To prove the concept of microwave filter and antenna, the operating centre frequency of 2 GHz is demonstrated and validated through simulation and measurement. The experimental shows promising results and in-line with the simulated results. This study is useful for any microwave system design where the reduction of overall physical volume and weight as well as cost is very important such as in base stations

Hybrid topology of substrate integrated waveguide (SIW) filter and microstrip patch antenna for wireless communication system

This paper presents an analysis based upon the resonant circuit approach to develop hybrid system for integrating a microwave filter and an antenna in a single device. This technique is used to reduce the overall volume of RF/ microwave front-end device especially in wireless communication systems. This study focuses on the hybrid of rectangular Substrate Integrated Waveguide (SIW) filter with rectangular microstrip patch antenna to produce filtering and radiating element in a single system. To prove the concept, the hybrid of microwave filter and antenna, the operating frequency of 2 GHz is demonstrated and validated through simulation and experimental. The experimental performance shows promising results which were in good agreement with the simulated results particularly in exhibiting return loss better than 10 dB in the passband region. This study is useful for any hybrid microwave system whereby it can reduce the complexity of the design, weight and cost as it is very important in base stations and multiplexer in any wireless communication systems