T-junction Power Divider Research Articles

Planar Rectangular Microstrip Patch Antenna Array with Corporate-Feed Network for Gain Enhancement

Abstract: The design and performance analysis of a inset-fed planar rectangular microstrip patch antenna array with corporatefeed network systems is presented in this paper. This design aims to increase the gain of the rectangular patch antenna through the use of a 16-element planar rectangular antenna array. Each element in this planar array is fed by T-junction power divider networks with quarter-wave transformer lines via the corporate-feed method. The antenna is designed over the operating frequency of 2.4 GHz using the substrate material FR-4, which has a dielectric constant of 4.4 and a loss tangent of 0.002. By the addition of radiating patches in the array design, the gain, directivity and bandwidth also has been improved significantly. The proposed antenna array provides a gain of 9.284 dB, a directivity of 16.2 dBi, and a bandwidth of 0.361 GHz. The designed antenna can be used for wireless applications.

C-Slot Circular Polarized Antenna for Hybrid Energy Harvesting and Wireless Sensing

This paper presents a new hybrid energy harvesting on electromagnetic solar for wireless energy harvesting of ambient from sensors of low-power devices. The axial ratio (AR) requirements produce Left-Hand Circular Polarization (LHCP) and Right-Hand Circular Polarization (RHCP) and simultaneously produce a 90-degree phase difference during energy harvesting, adopting a new design in designing a dual-feed broadband circular polarized (CP) antenna. To get the frequency band 2.3–2.4 GHz, we propose a C-Slot antenna with a circular patch dual feed. To estimate the diversity of the phase and magnitude output of the feed configuration under AR value, we used a 50 Ohm feed network output of the characteristic analysis for a dual feed CP antenna. An Axial ratio frequency range of less than 3 dB is achieved using polarization analysis with different branch channel couplers. To produce a DC output voltage, a high-frequency rectifier circuit embedded with a thin-film solar cell on the antenna is then connected to two T-junction power divider rectifiers, resulting in a high-efficiency design. A complete system-level analysis will include multiple signal classification methods of powered ambient RF energy using a wireless energy harvesting array that proposes a compact structure and demonstrates optimal configuration. Reliable operation in typical indoor environments indicates a self-contained sensor Node. Therefore, it has significant implications for powering small electronics and wireless sensor applications independently of the IoT Network or real implementation telecommunications industry.

A high-order TE50 mode waveguide with single mode transmission property and its application in slot array antenna

Conventional array antenna techniques contain various feeding networks, such as T-junction power dividers, phase dividers, and baluns. To feed a relatively large array, one can cascade the traditional T-junction power dividers, resulting in the increase of design complexity. In this paper, an overmoded waveguide supporting the single mode propagation of TE50 mode, is presented. Since TE50 mode can be separated into five TE10 modes with equi-amplitude and opposite phase properties, it is advisable to distribute the input signal flexibly and decrease the cascading of the T-junctions for the traditional feeding networks. To actualize a TE50 mode waveguide, several rows of metallic blocks acting as metamaterial are periodically loaded inside an overmoded waveguide to tailor the dispersion of the waveguide modes and yield the proposed mode bandgaps. Considering the Bloch theory, parts of the undesired waveguide modes are not supported inside the metamaterial and will be removed by these bandgaps. In addition, central feeding method is used to suppress the unwanted modes further in light of mode mismatch. As a proof-of-concept, we drilled the slot array on the top of the overmoded waveguide directly and give rise to a pencil beam radiation along the broadside with 15–17 dBi realized gain among 9.4–10.6 GHz, which demonstrates the stable feeding ability of TE50 mode.

3-D-Printed Dual-Band Rectenna System for Green IoT Application

This paper describes the novel fully 3D-printed dual-band RF energy harvester suitable for wireless sensor network green IoT applications. The proposed energy harvesting system is composed of a dual-band circular omnidirectional monopole antenna array with a T-junction power divider, RF rectifier, and an impedance matching network. The circular monopole antenna array is conformed to a cylindrical substrate to achieve the compact system. The Villard multiplier-based rectifier has been used for the conversion of RF signal to DC voltage. The presented rectenna is fabricated using a 3D printable, biodegradable, conformal and an economical substrate. The test is performed in an RF ambient environment. The manufactured configuration obtained conversion efficiencies of 67.29% with output voltage of 1.39 V and 42.16% with output voltage of 1.1 V at 0 dBm RF input power in 2.4 GHz and 5.2 GHz frequency bands respectively. The proposed configuration’s simulated and measured results are in concordance with each other. The study emphasizes the potential of 3D-printed rectenna in terms of cost-effective prototyping.

Dual-Polarized Wideband Low-Sidelobe Slot Array Antenna for V-Band Wireless Communications

A dual-polarized wideband low sidelobe slot array antenna for wireless communication systems in the V-band is proposed in this work. Taylor distribution is applied with each radiating slot as a tapering unit in both polarizations. A compact 2 × 2 elements subarray is designed to achieve stable amplitude and phase distribution among elements with two sets of integrated compact wideband unequal power dividers for the E- and H-planes inside the subarray. Then, two layers of orthogonally polarized feeding networks with unequal E-plane T-junction power dividers are used to connect the subarrays to two standard waveguides WR-15 as input ports. The prototype of 8 × 8 elements is fabricated and measured in an anechoic chamber. The maximum measured gain is 25.3 dBi and 25.4 dBi for V- and H-polarization, respectively. The overlapped impedance bandwidth is from 57 to 66.4 GHz with reflection coefficiencies below -10 dB, and the isolation between two input ports is around 35 dB. Sidelobe levels of both polarizations are below -22 dB with good agreement with the simulations.

A High-Power 170 GHz in-Phase Power-Combing Frequency Doubler Based on Schottky Diodes.

In this paper, a high-power 170 GHz frequency doubler based on a Schottky diode is proposed using an in-phase power-combining structure. Unlike a conventional power-combining frequency doubler, the proposed frequency doubler utilizes the combination of a T-junction power divider and two bend waveguides to eliminate the phase difference between the two output ports of the T-junction power divider, so as to achieve in-phase power combining with a concise structure. The frequency doubler was fabricated on a 50 μm thick AlN high-thermal-conductivity substrate to reduce the impact of the thermal effect on the performance. The measured results show that the doubler exhibits a conversion efficiency of 11-31.3% in the 165-180 GHz band under 350-400 mW of input power, and a 118 mW peak output power with a 31.3% efficiency was measured at 174 GHz `when the input power was 376 mW. A good agreement was achieved between the simulation results and the measured performance of the doubler, which proves the effectiveness of the proposed in-phase power-combining structure.

A Simple Way to Enhance the Isolation of Ridge Gap Waveguide T-Junction, for Application to Millimeter-Wave Feeder Networks

In this letter, a simple technique for enhancing the isolation of a ridge-gap waveguide (RGW) T-junction power divider is proposed. In detail, we have succeeded in improving the isolation characteristics of a normal T-junction by a factor of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\sim$</tex-math> </inline-formula> 10 ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$&gt;$</tex-math> </inline-formula> 15-dB), while the operation is simply the introduction of an appropriately sized radiation slot in its lid. Compactness is, therefore, the primary advantage of this solution, as there is no need to use any load terminations. Such a quasiplanar configuration means that it can be applied to large-scale feeder networks like an original T-junction (regardless of vertical or horizontal space constraints when ranking the array). A four-way feeder prototype operating in the W-band was fabricated to validate the scheme, and the measured results showed good agreement with the simulated predictions, both demonstrating excellent RF performance.

A 3-D Metal-Printed Dual-Polarized Ridged Waveguide Slot Array Antenna for X-Band Applications

A compact three-dimensional (3-D) metal-printed ridged waveguide slot array antenna with wideband, dual linear polarization and low cross-polarization is presented for X-band applications. The proposed design achieves a compact structure due to the method of using a ridged waveguide (RWG). A vertically linear polarized (VP) array is realized through eight longitudinal shunt slots etched on the non-ridged broad wall of the RWG, while a horizontally linear polarized (HP) array is realized through eight V-shaped slots cut on the ridged broad wall of the RWG. To extend the operating bandwidth, each 1 × 8-element linear array is separated into two 1 × 4-element sub-arrays through a central feeding technique. The two sub-arrays of the VP array are excited with equal amplitude and are 180° out-of-phase through a T-junction power divider, which connects the coaxial feed and the radiated waveguide, while the two HP subarrays are directly excited by a coaxial feed with equal amplitude and remain in phase. The feed structure uses coaxial probes directly attached to the RWG to provide good mechanical stability and low voltage around the feed. An optimized 2 × 8-element dual-polarized array is fabricated using 3-D metal-printing technology for experimental verification. The measured −10 dB impedance bandwidth of the VP array is 1.2 GHz (12.2%) and, of the HP array, is 1.1 GHz (11.2%) with maximum gains of 14.6 and 15.5 dBi, respectively. There is good polarization purity over the entire operating bandwidth with a cross-polarization level better than −40 dB in the main beam direction. The isolation between two orthogonal polarized arrays is greater than 40 dB over the whole band.

Compact Wideband Double-Slot Microstrip Feed Engraved TEM Horn Strip Antennas on a Multilayer Substrate Board for in Bed Resting Body Positions Determination Based on Artificial Intelligence

In this paper, a horn-shaped strip antenna exponentially tapered carved on a multilayer dielectric substrate for an indoor body position tracking system is proposed. The performance of the proposed antenna was verified by testing it as a tracking state of an indoor resting body position. Among different feeding techniques, the uniplanar T-junction power divider approach is used. The performance verification of the proposed antenna is explained through its compact size and 3D shape, along with a performance comparison of the return loss radiation pattern and the realized gain. The suggested antenna has an 88.88% fractional bandwidth and a return loss between 6 and 15.6 GHz, with a maximum gain of 9.46 dBi in the 9.5 GHz region. Within the intended band, the radiation pattern had an excellent directivity characteristics. The proposed antenna was connected to an NVA-R661 module of Xethru Inc. for sleeping body position tracking. The performance of the antenna is measured through microwave imagining of the state of the resting body in various sleeping positions on the bed using a Recurrent Neural Network (RNN). The predicted outcomes clearly define the antenna's performance and could be used for sensing and prediction purposes.

Grating Lobes Reduction in an Array Antenna Using Curved Disc Monopoles

This paper shows the study of an array antenna with curved disc monopoles whose average spacing between elements is greater than a wavelength l0. The proposed antenna is a linear array, consisting of four equally spaced curved disc monopoles excited by a corporate feed (T-junction power divider). The single element is characterized by a directional radiation pattern in the H plane. Compared to an isotropic monopole antenna array, the proposed array reduces the grating lobes to more than -15dB. As a result, the gain will be increased. The array antenna is fabricated and measured for its impedance and radiation characteristics. The results of the simulation and measurement are in good agreement.

SIW-based dual-beam conical conformal slot array antenna for X-band applications

Abstract A design of substrate integrated waveguide (SIW) based conical conformal slot array antenna is presented for X-band applications. The proposed design consists of two SIW arrays of 1 × 6 slot radiators located at ϕ = 0° and ϕ = 180°. The slotted arrays are fed using a rectangular waveguide (RWG) to SIW 1 × 2 T-junction power divider. The arrays are projected in the longitudinal direction on a conical surface having a lower and upper radius of 1.66λ 0 and 1.33λ 0, respectively. The power divider and SIW arrays are designed and simulated in full-wave EM simulation software. It is observed from the results that the proposed array has two main beams in the H-plane located at θ = ± ${\pm}$ 90°, and have sidelobe levels (SLLs) of −23 dB and −20 dB, respectively. For the validation of simulation results, the proposed array is fabricated and measured, and a reasonable agreement is observed between both results.

A compact high gain wideband millimeter wave 1 × 2 array antenna for 26/28 GHz 5G applications

PurposeThis paper aims to present the design, fabrication and analysis of a wideband, enhanced gain 1 × 2 patch antenna array with a simple profile structure to meet the desired antenna traits, such as wide bandwidth, high gain and directional patterns expected for the upcoming fifth-generation (5G) wireless applications in the millimeter wave band. To enhance these parameters (bandwidth and gain), a new antenna geometry by using a T-junction power divider is presented.Design/methodology/approachThe theory behind this paper is connected with advancements in the 5G communications related to antennas. The methodology used in this work is to design a high gain array antenna and to identify the best possible power divider to deliver the power in an optimized way. The design methodology adopts several steps like the selection of proper substrate material as per the design specification, size of the antenna as per the frequency of operation and application-specific environment condition. The simulation has been performed on the designed antenna in the electromagnetic simulation tool (high-frequency structure simulator [HFSS]), and optimization has been done with parametric analysis, and then the final array antenna model is proposed. The proposed array contains 2-patch elements excited by one port adapted to 50 Ω through a T-junction power divider. The 1 × 2 array configuration with the suggested geometry helps to improve the overall gain of the antenna, and the implementation of the T-junction power divider provides enhanced bandwidth. The proposed array designed using a 1.6 mm thick flame retardant substrate occupies a compact area of 14 × 12.14 mm2.FindingsThe prototype of the array antenna is fabricated and measured to validate the design concept. A good agreement has been reached between the measured and simulated antenna parameters. The measured results confirm its wideband and high gain characteristics, covering 24.77–28.80 GHz for S11= –10 dB with a peak gain of about 15.16 dB at 27.65 GHz.Originality/valueThe proposed antenna covers the bandwidth requirements of the 26 GHz n258 band (24.25–27.50 GHz) to be deployed in the UK and Europe. The suggested antenna structure also covers the federal communications commission (FCC)-regulated 28 GHz n261 band (27.5–28.35 GHz) to be deployed in America and Canada. The low profile, compact size, simple structure, wide bandwidth, high gain and desired directional radiation patterns confirm the applicability of the suggested array antenna for the upcoming 5 G wireless systems.

Design and Simulation “Ha”-Slot Patch Array Microstrip Antenna for WLAN 2.4 GHz

This paper presents a linear 1 × 2 “Ha ( )”–slot patch array microstrip antenna. The proposed design of an array microstrip antenna is intended for Wireless Local Area Network (WLAN) 2.4 GHz devices. From the previous research concerning the single patch “Ha ( )”–slot microstrip antenna, the gain that can be achieved is 5.77 dBi in simulation. This value is considered too small for an antenna to accommodate WLAN devices if compare to a Hertzian antenna. To enhance the gain of microstrip antenna, some methods can be considered using linear 1 × 2 patch array and T-Junction power divider circuit to have matching antenna impedance. The distances between two patches are one of the important steps to be considered in designing the patch array microstrip antenna. Thus, the minimum distance between the patch elements are calculated should be greater than λ/2 of the resonance frequency antenna. If the distance less than λ/2 electromagnetically coupled will occur, vice versa when it is to widen the dimension of the antenna will less efficient. Epoxy substrate Flame Resistant 4 (FR4) with dielectric constant 4.3 is used as the platform designed for the array antenna and it is analyzed using simulation software Computational Simulation Technology (CST) studio suite by which return loss, Voltage Standing Wave Ratio (VSWR), and gain are calculated. The simulation result showed that the designed antenna achieve return loss (S11) -25.363 dB with VSWR 1.1 at the frequency 2.4 GHz, and the gain obtained from simulation is 8.96 dBi, which is greater than 64.4 % if compared to the previous one. The proposed antenna design shows that increasing the number of patches in the array can technically improve the gain of a microstrip antenna, which can cover a wider area if applied to WLAN devices

T-Junction Power Divider Based on Rectangular Microcoaxial Structure in W-band

In this paper, a W-band T-junction power divider based on rectangular microcoaxial structure is proposed. Rectangular microcoaxial line is a three dimensional (3D) structure with the merits of wide operation bandwidth, low loss and high integration, which is suitable for the design of radio frequency (RF) devices. A two-way power divider is designed based on the rectangular microcoaxial structure. And the two-way power divider is expanded into a four-way power divider to further illustrate the design method. Moreover, a back-to-back configuration including two identical two-way power divider is fabricated and measured. The insertion loss of the back-to-back configuration is about 0.11-1.18 dB in W band, which agrees with the simulation one reasonably and shows good performance.

Dual-Polarized Slot Antenna for Full-Duplex Systems With High Isolation

A single-layered slot antenna system working at 5.8 GHz Industrial, Scientific and Medical (ISM) band is proposed for in-band full duplex (IBFD) operation applications without the use of a coupler. First, high isolation is achieved by strong separation of even- and odd-mode feeds. The microstrip-coupled coplanar waveguide (CPW) is used at Port 1 (TX port) to excite a stepped-slot antenna in the CPW odd mode. On the opposite side, a microstrip T-junction power divider is employed at Port 2 (RX port) to feed two offset-fed stepped-slot antennas in even mode. Second, isolation is further improved by 30 dB by using a lumped capacitor at the termination of the CPW. The measured isolation between the two ports is about 50 dB across the bandwidth. The measured −10 dB bandwidth of Port 1 is 0.49 GHz (8.5%), while that of Port 2 is 1.06 GHz (18.3%). The gains of TX and RX antennas are 5.4 and 5.8 dBi at 5.8 GHz. The proposed antenna can also be deployed as a dual-polarized antenna. Mathematical analysis and equivalent transmission line circuit models are provided to give physical insight into the working principals of the antenna with validation from ANSYS HFSS simulation.

Performance Enhancement of mm-Wave Phased Arrays for Mobile Terminals Through Grounded Coplanar Waveguide Feeding Networks With via Fences

This paper presents a design methodology focused on feeding networks that can improve the insertion loss and coverage efficiencies of millimeter-wave (mm-Wave) phased arrays in mobile terminals. This enhancement is accomplished by using a grounded coplanar waveguide (GCPW) transmission line (TL) withviafences fabricated on single-layer FR-4 PCB. The exemplified 8-element phased arrays incorporating a compact one-dimensional electromagnetic bandgap (1-D EBG) antenna are fed through a 1 × 8 T-junction power divider, which includes the predetermined phased delay lines. To achieve high radiation performance with minimum leakage power or spurious waves in the T-junction power divider, an island-shape GCPW TL topology withviafences featuring high-impedance surfaces (HIS) is devised and fabricated. For further investigation on the radiation performance and spherical coverage of the mm-Wave mobile antenna, a mobile device prototype equipped with two sets of the 8-element phased arrays is prepared and studied. Through extensive simulation and experimental studies, it can be ascertained that the proposed GCPW TL topology withviafences can improve the realized gain at a coverage efficiency of 50% by more than 3 dB, between 26 and 36 GHz.

LHCP four patches stack triangular truncated antenna using corporate feed microstrip-line for CP-SAR sensor

&lt;span&gt;In this paper, we acquire the configuration of the left-hand circular polarization (LHCP) array four patches stack triangular truncated microstrip antenna. This construction use the basic corporate feed microstrip-line with modified lossless T-junction power divider on radiating patch for circularly polarized-synthetic aperture radar (CP-SAR) sensor embedded on unmanned aerial vehicle (UAV) with compact, small, and simple configuration. The design of circular polarization (CP) is realized by truncating the whole three tips and adjusting the parameters of antenna at the target frequency, &lt;em&gt;f &lt;/em&gt;= 5.2 GHz. The results of characteristic performance and &lt;em&gt;S&lt;/em&gt;-parameter for the LHCP array four patches stack antenna at the target frequency show successively about 9.74 dBic of gain, 2.89 dB of axial ratio (&lt;em&gt;Ar&lt;/em&gt;), and &lt;/span&gt;&lt;span&gt;-&lt;/span&gt;&lt;span&gt;10.91 dB of S-parameter. Moreover, the impedance bandwidth and the 3 dB-&lt;em&gt;Ar&lt;/em&gt; bandwidth of this antenna are around 410 MHz (7.89%) and 100 MHz (1.92%), respectively.&lt;/span&gt;

Vivaldi Antenna Arrays Feed by Frequency-Independent Phase Shifter for High Directivity and Gain Used in Microwave Sensing and Communication Applications.

This paper describes a novel feed system for compact, wideband, high gain six-slot Vivaldi antenna arrays on a single substrate layer using a unique combination of power splitters based on binary T-junction power splitter topology, frequency-independent phase shifter, and a T-branch. The proposed antenna system consists of six Vivaldi antennas, three on the left, and three on the right arm. Each arm connects with T-junction power divider splitter topology, given that the right arm is linked through a frequency-independent phase shifter. Phase shifters ensure that the beam is symmetrical without splitting in a radiating plane so that highly directive radiation patterns occur. The optimal return losses (S-parameters) are well enriched by reforming Vivaldi’s feeding arms and optimizing Vivaldi slots and feeds. A novel feature of our design is that the antenna exhibits the arrangements of a T-junction power splitter with an out-of-phase feeding mechanism in one of the arms, followed by a T-branching feeding to even arrays of proper Vivaldi antenna arrangement contributing high realized gain and front-to-back ratio up to 14.12 dBi and 23.23 dB respectively applicable for not only ultra-wideband (UWB) application, also for sensing and position detecting. The high directivity over the entire UWB frequency band in both higher and lower frequency ranges ensures that the antenna can be used in microwave through-wall imaging along with resolution imaging for ground penetration radar (GPR) applications. The fabricated antenna parameters are in close agreement with the simulated and measured results and are deployed for the detection of targets inside the voids of the concrete brick.

Wideband Design of a Compact Monopole-Like Circular Patch Antenna Using Modal Analysis

In this letter, we present a systematic approach to design a compact dual-mode monopole-like patch antenna using characteristic mode analysis (CMA). The modal analysis of a slotted circular patch structure incorporating a new shorting pin loading technique is presented. To achieve a compact monopole-like antenna with the wideband operation, it is demonstrated that the first two significant modes with monopole-like patterns are the most suitable ones for dual-mode excitation. Based on the analysis of the modal currents and electric fields, four groups of shorting pins and four slots are introduced to individually tune the two modes, which facilitates the optimization. The effects of these slots and shorting pins on the resonant frequencies of the two modes are analyzed in detail. Finally, a CPW T-junction power divider is applied to simultaneously excite these two modes and suppress the undesired modes. Apart from a more compact form factor and higher gain than existing work, it also features a competitive gain-bandwidth per volume ratio.

Flexible ultra‐high transformation ratio‐based dual‐band impedance transformer and its applications in a T‐junction power divider

A design scheme is presented for an all-pass coupled-line (APCL)-based dual-band impedance-matching network. Salient features include a highly flexible frequency ratio (r) (high of 15 and low of 1.2) and impedance transformation ratio (k) (high of 9 and low of 0.2) simultaneously at two arbitrary, uncorrelated frequencies of interest. The design strategy consists of two APCL sections and a stub that prove to be simple and easy to prototype. Detailed mathematical modelling and graphical interpretations have been presented. Closed-form design equations have been developed and backed up with design examples. Two dual-band T-junction power dividers (TPDs) have been designed to demonstrate the application of the proposed impedance transformer at two widely separated frequencies. RO4350 B- and RO5880-based prototypes have been fabricated for both the matching network and the TPD to validate the proposed theory. The measurement results demonstrate an achievable frequency ratio of 15 and an impedance transformation ratio of 9 in simultaneous operation mode.