scholarly journals Unbalanced Two-Way Filtering Power Splitter for Wireless Communication Systems

Electronics ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 617
Author(s):  
Augustine O. Nwajana ◽  
Gerald K. Ijemaru ◽  
Kenneth L.-M. Ang ◽  
Jasmine K. P. Seng ◽  
Kenneth S. K. Yeo

A compact unbalanced two-way filtering power splitter with an integrated Chebyshev filtering function is presented. The design is purely based on formulations, thereby eliminating the constant need for developing complex optimization algorithms and tuning, to deliver the desired amount of power at each of the two output ports. To achieve miniaturization, a common square open-loop resonator (SOLR) is used to distribute energy between the two integrated channel filters. In addition to distributing energy, the common resonator also contributes one pole to each integrated channel filter, hence, reducing the number of individual resonating elements used in achieving the integrated filtering power splitter (FPS). To demonstrate the proposed design technique, a prototype FPS centered at 2.6 GHz with a 3 dB fractional bandwidth of 3% is designed and simulated. The circuit model and layout results show good performances of high selectivity, less than 1.7 dB insertion loss, and better than 16 dB in-band return loss. The common microstrip SOLR and the microstrip hair-pin resonators used in implementing the proposed integrated FPS ensures that an overall compact size of 0.34 λg × 0.11 λg was achieved, where λg is the guided-wavelength of the 50 Ω microstrip line at the fundamental resonant frequency of the FPS passband.

Electronics ◽  
2021 ◽  
Vol 10 (18) ◽  
pp. 2254
Author(s):  
Luyan Qiao ◽  
Rui Li ◽  
Ying Han ◽  
Feng Wei ◽  
Yong Yang ◽  
...  

In this paper, a balanced-to-balanced filtering directional coupler (FDC) that can realize a 3 dB coupling degree directional coupler with high isolation and directivity is proposed. The design of the proposed FDC is primarily based on microstrip/slotline transition structures, resonance structures, and odd–even mode phase velocity compensation structures. A U-type microstrip feed line integrated with a stepped-impedance slotline resonator is adopted at the input and output ports, which makes the differential-mode (DM) responses independent of the common-mode (CM) ones, and brings superior DM transmission and CM suppression. In addition, by loading the microstrip stub-loaded resonators (SLRs), a DM passband with sharp filtering performance is realized, and transmission zeros (TZs) can be added into the design, which makes it more selective. Moreover, phase compensating slotlines are added into the coupling structure to enhance the isolation. In order to verify the feasibility of the proposed design method, an FDC prototype circuit was made and tested. The simulation results are in good agreement with the measured results. The designed coupler’s DM operating band covers 2.65 GHz to 3 GHz (FBW = 12.4%), and the insertion and return losses are 4.6 dB and 20 dB, respectively. The isolation degree is better than 15 dB, and the CM suppression is more than 55 dB. The total coupler size is about 67.7 mm × 63.8 mm. The designed balanced-to-balanced FDC can be widely used in S-band wireless communication systems.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Basem Aqlan ◽  
Mohamed Himdi ◽  
Hamsakutty Vettikalladi ◽  
Laurent Le-Coq

AbstractA low-cost, compact, and high gain Fabry–Perot cavity (FPC) antenna which operates at 300 GHz is presented. The antenna is fabricated using laser-cutting brass technology. The proposed antenna consists of seven metallic layers; a ground layer, an integrated stepped horn element (three-layers), a coupling layer, a cavity layer, and an aperture-frequency selective surface (FSS) layer. The proposed aperture-FSS function acts as a partially reflective surface, contributing to a directive beam radiation. For verification, the proposed sub-terahertz (THz) FPC antenna prototype was developed, fabricated, and measured. The proposed antenna has a measured reflection coefficient below − 10 dB from 282 to 304 GHz with a bandwidth of 22 GHz. The maximum measured gain observed is 17.7 dBi at 289 GHz, and the gain is higher than 14.4 dBi from 285 to 310 GHz. The measured radiation pattern shows a highly directive pattern with a cross-polarization level below − 25 dB over the whole band in all cut planes, which confirms with the simulation results. The proposed antenna has a compact size, low fabrication cost, high gain, and wide operating bandwidth. The total height of the antenna is 1.24 $${\lambda }_{0}$$ λ 0 ($${\lambda }_{0}$$ λ 0 at the design frequency, 300 GHz) , with a size of 2.6 mm × 2.6 mm. The proposed sub-THz waveguide-fed FPC antenna is suitable for 6G wireless communication systems.


2020 ◽  
Vol 41 (3) ◽  
Author(s):  
Farhad Fouladi ◽  
Abbas Rezaei

In this paper, a six-channel microstrip diplexer is designed and fabricated. It operates at 0.75/0.85/1/1.25/1.6/1.8 GHz for multi-service wireless communication systems. It consists of two stub-loaded resonators, which are integrated by coupled lines. The channels are close together, which makes the proposed diplexer suitable for frequency division duplex (FDD) schemes. The proposed structure has a compact size of 0.025 λg2 where λg is the guided wavelength calculated at 0.75 GHz. The other advantages of the introduced multi-channel diplexer are the low insertion losses of 1.62/1.27/0.43/0.53/1.26 and 1 dB, as well as good return losses of 26/26/25/25/21.7 and 22 dB at 0.75/0.85/1/1.25/1.6/1.8 GHz respectively. A good isolation of less than 22 dB is obtained between the channels. In order to design the presented diplexer a designing technique is used which is based on the proposing of an equivalent approximated LC model and calculating the inductors and capacitors. To confirm the simulation results, the introduced diplexer is fabricated and measured.


2016 ◽  
Vol 2016 ◽  
pp. 1-6 ◽  
Author(s):  
Weiping Li ◽  
Zongxi Tang ◽  
Xin Cao

In this article, a compact narrow-bandpass filter with high selectivity and improved rejection level is presented. For miniaturization, a pair of double negative (DNG) cells consisting of quasi-planar chiral resonators are cascaded and electrically loaded to a microstrip transmission line; short ended stubs are introduced to expand upper rejection band. The structure is analyzed using equivalent circuit models and simulated based on EM simulation software. For validation, the proposed filter is fabricated and measured. The measured results are in good agreement with the simulated ones. By comparing to other filters in the references, it is shown that the proposed filter has the advantage of skirt selectivity and compact size, so it can be integrated more conveniently in modern wireless communication systems and microwave planar circuits.


Electronics ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 601
Author(s):  
Adnan Ghaffar ◽  
Xue Jun Li ◽  
Wahaj Abbas Awan ◽  
Aqeel Hussain Naqvi ◽  
Niamat Hussain ◽  
...  

This research article proposes a compact frequency and pattern reconfigurable flexible antenna for heterogeneous applications. A triangular monopole antenna with a semicircular stub is made frequency and pattern tunable by connecting and disconnecting two inverted L-shaped stubs utilizing diodes. When either of the stubs is connected to the radiator, a relative phase difference happens at both ends of the radiator that changes the direction of the electromagnetic radiations, consequently pattern reconfigurability can be obtain. Besides that, because of the reactive load introduced by the stubs, the antenna’s effective length has changed and, as a result, the frequency reconfigurability can be attained. The antenna features a compact size of 40 × 50 × 0.254 mm3 corresponding to 0.22λo × 0.27λo × 0.001λo, where λo is free-space wavelength at 1.65 GHz, while its operational bandwidth is from 1.65 GHz to 2.51 GHz, with an average gain and radiation efficiency of better than 2.2 dBi and 80%, exhibiting a pattern reconfigurability of 180° in the E-plane. The frequency of the proposed antenna can be switched from 2.1 GHz to 1.8 GHz by switching the state of both diodes in OFF and ON-state, respectively. The fabricated prototype of the antenna is tested to verify its performance parameters. In addition, to validate the proposed design, it has been compared with prior arts in terms of the overall size, reconfigurability type, flexibility, radio frequency (RF) switch type used for reconfigurability, and frequency bandwidth. The proposed antenna provides smaller size with a large bandwidth coverage alongside with discrete RF switch type with the advantages of flexibility and both frequency and pattern reconfigurability. As a result, the proposed compact flexible and pattern reconfigurable antenna is a promising candidate for heterogeneous applications, including the global system for mobile (GSM) band (1800 and 1900 MHz) and industrial, scientific and medical (ISM) band (2.4 GHz) along with well-known cellular communication bands of 3G, 4G, and long term evolution (LTE) bands ranging from 1700–2300 MHz around the globe.


Author(s):  
Mai Thanh Nga ◽  
Vu Van Yem ◽  
Nguyen Huu Thanh ◽  
Pham Duy Phong

UMTS (Universal Mobile Telecommunications System) technology is one of the third-generation (3G) cell phone technologies, which is also being developed into a 4G technology. Although UMTS2001 is the most widely-deployed UMTS band, some countries utilize 1900 MHz instead. Besides, the co-existing GPS (Global Positioning System) operates at the frequency of 1575 MHz. Thus, a desirable antenna in UMTS systems needs to cover both of two bands in order to operate in various devices. This paper will propound an antenna covering the range of frequencies from 1.53 GHz to 2.53 GHz that includes 1.575 GHz, 1.8 GHz, 1.9 GHz ,and 2.1 GHz. The developed quasi-Yagi antenna has a simple-low profile and achieves a bandwidth of 48%, a front- to- back ratio of 19 dB, a gain of 6dBi, and an efficiency of better than 78% at 2.1GHz. In this paper, the study on effects of parameters of the antenna is also investigated to achieve optimal model.


Author(s):  
Sunil Raosaheb Gagare . ◽  
Dolly Reney .

The new design methods of microwave filter has proved its significance for use in wireless communication systems. Modern wireless communication systems require microwave filters to have stringent specifications such as compact size, robust, conformal, light weight and more importantly cost effective while maintaining its electrical characteristics. Micro-strip filter design and reconfigurable filters present a better prospectus in this regards as it meets the specifications of modern wireless communication applications. Reconfigurable filters can provide control over parameters such as frequency, bandwidth and selectivity while reducing the need of number of switches sandwiched between electrical components. Different methods have provided a new dimension for designing microwave filters .In this article, we present a review on design methods for reconfigurable band-pass filters for next generation wireless technologies such as 4G, 5G and IOT.


2017 ◽  
Vol 2017 ◽  
pp. 1-7 ◽  
Author(s):  
Yao Chen ◽  
Longfang Ye ◽  
Jianliang Zhuo ◽  
Yanhui Liu ◽  
Liang Zhang ◽  
...  

In this paper, a compact frequency reconfigurable circular patch antenna with an arc-shaped slot loaded in the ground layer is proposed for multiband wireless communication applications. By controlling the ON/OFF states of the five PIN diodes mounted on the arc-shaped slot, the effective length of the arc-shaped slot and the effective length of antennas current are changed, and accordingly six-frequency band reconfiguration can be achieved. The simulated and measured results show that the antenna can operate from 1.82 GHz to 2.46 GHz, which is located in DCS1800 (1.71–1.88 GHz), UMTS (2.11–2.20 GHz), WiBro (2.3–2.4 GHz), and Bluetooth (2.4–2.48 GHz) frequency bands and so forth. Compared to the common rectangular slot circular patch antenna, the proposed arc-shaped slot circular patch antenna not only has a better rotational symmetry with the circular patch and substrate but also has more compact size. For the given operating frequency at 1.82 GHz, over 55% area reduction is achieved in this design with respect to the common design with rectangular slot. Since the promising frequency reconfiguration, this antenna may have potential applications in modern multiband and multifunctional mobile communication systems.


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