Hybrid Power Divider Research Articles

Hybrid Power Divider and Combiner for Passive RFID Tag Wireless Energy Harvesting

This paper presents three- and five-ports radio frequency (RF) hybrid power divider combiner (HPDC) designs with multiband characteristics operating at 2.4 GHz (ISM, IEEE 802.11b,g); 5.8 GHz (IEEE 802.11n, a and 802.11ac); and 6 GHz (IEEE 802.11ax) wireless standards for energy-efficient 5G-enabled passive Internet of Things (IoT) sensors; energy harvesting (E.H); passive radio frequency identification (RFID) tags; multiple-input multiple-output (MIMO) antenna beamforming; and data communication applications spanning DC to the 6-GHz frequency range. The presented HPDC designs operate at a centre-design frequency of 3 GHz on a Rogers RO4350 substrate. The designed novel HPDC demonstrates a good match between the ports, high isolation between the output ports, and equal power distribution between the output ports. Furthermore, the obtained return and isolation losses are less than −10 dB for the Wi-Fi 6E standards. The reported findings hold an excellent promise for RF energy harvesting and utilisation, adaptive intelligent energy-efficient data communication, and seamless ubiquitous satellite-cellular convergence connectivity applications.

Gecko‐Gaskets for Multilayer, Complex, and Stretchable Liquid Metal Microwave Circuits and Antennas

AbstractThis paper describes a reliable, repeatable, and cost effective solution for fabrication of complex mechanically reconfigurable microfluidic devices for soft electronics. The devices are made of eutectic gallium indium (EGaIn) in styrene‐ethylene‐butylene‐styrene thermoplastic elastomer with gecko‐adhesive based bonding which both aids in sealing thin channels and directing flow of high surface energy metal into small channels in a repeatable process. Selective filling of complex microfluidic structures is achieved by controlled advancement of EGaIn‐air interface using optimized hydrophobic valves. These valves are designed based on EGaIn's critical Laplace pressure to fabricate variable aspect ratio and multilayer features or designs with multiple branches and arrays of isolated elements. As a proof of concept, different antennas (bow‐tie, folded and multilayer dipoles, and microstrip patch antennas) and a hybrid power divider are fabricated with total device thicknesses less than 600 µm. These devices can conform to complex surfaces for applications like body worn sensors, and can be stretched or bent to change their electromagnetic properties such as center frequency, bandwidth, and impedance matching.

High-performance cryogenic fractal 180° hybrid power divider with integrated directional coupler

A 180° hybrid and a directional coupler to be employed in the P-band cryogenic receiver of the Sardinia Radio Telescope are proposed in this work. An in-depth study of the issues related to the use of microwave components for cryogenic radio astronomy receivers is carried out to select the best suited technology and configuration. As a result, a planar fractal 180° hybrid configuration available in the literature has been optimized aiming to increase the operating bandwidth in order to comply with the design specifications of the application at hand. A coupled lines directional coupler with weak coupling and high isolation, used to calibrate the receiver chain, is cascaded to the 180° hybrid and realized in the same layout. The final device, consisting of the 180° hybrid and the directional coupler, has been manufactured and tested at the cryogenic temperature of 20 K, showing a good agreement between experimental results and predicted performance.

Double Ridged 180<formula formulatype="inline"><tex Notation="TeX">$^{\circ}$</tex></formula> Hybrid Power Divider With Integrated Band Pass Filter

We describe the design, construction and performance of a 180° hybrid power divider with integrated band pass filter for L-band (1.3-1.8 GHz). The hybrid is based on a cavity and two novel broadband coaxial-to-double ridged waveguide transitions. The design was optimized using a commercial 3-D electromagnetic simulator. The device was tested at room and cryogenic temperature. At the physical temperature of 77 K the measured input reflection was less than -17 dB, the maximum deviation from the ideal -3 dB coupling and 180° phase difference were, respectively ±0.25 dB and ±0.9°. The experimental results are in good agreement with simulation.

Hybrid Wideband Microstrip Wilkinson Power Divider Based on Lowpass Filter Optimized Using Particle Swarm Method

In this paper, an optimized microstrip hybrid 3-stage Wilkinson power divider based on lowpass filter is presented. The particle swarm optimization (PSO) method and method of moment (MoM) have been used to broaden the bandwidth to effectively cover 2–8 GHz ultra wideband range which is equal to 120% fractional bandwidth and to reject higher frequencies. The dimensions of filtering blocks and also Wilkinson isolating resistors are all used as optimization variables. The fitness function is evaluated by MOM simulations, and the MoM is used to calculate the response of the proposed Wilkinson power divider. A prototype hybrid power divider based on lowpass filter is then fabricated and measured to provide an experimental verification on the predicted features. Finally, both the method of moment and finite elements method are used to simulate the s-parameters. Simulation results on insertion loss and isolation of the implemented power divider are compared with measured values, and results for return loss is obtained using MoM and finite elements method.

CLOSED-FORM DESIGN METHOD OF AN N-WAY DUAL-BAND WILKINSON HYBRID POWER DIVIDER

In this paper, the closed-form design method of an N- way dual-band Wilkinson hybrid power divider is proposed. This symmetric structure including N groups of two sections of transmission lines and two isolated resistors is described which can split a signal into N equiphase equiamplitude parts at two arbitrary frequencies (dual-band) simultaneously, where N can be odd or even. Based on the rigorous even- and odd-mode analysis, the closed-form design equations are derived. For veriflcation, various numerical examples are designed, calculated and compared while two practical examples including two ways and three ways dual-band microstrip power dividers are fabricated and measured. It is very interesting that this generalized power divider with analytical design equations can be designed for wideband applications when the frequency-ratio is relatively small. In addition, it is found that the conventional N-way hybrid Wilkinson power divider for single-band applications is a special case (the frequency-ratio equals to 3) of this generalized power divider.

UWB antenna array for wireless transmission along corridors

AbstractA 2‐element elliptical patch antenna array with a bidirectional radiation pattern has been developed for ultra wideband indoor wireless communications. The array is constructed by means of feeding two omni‐directional elliptical patch elements with a 3‐section hybrid power divider. Experimental results show that the array has a stable radiation pattern and low return loss over a broad bandwidth of 64% (3.1–6 GHz). © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 886–890, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23232

Lumped-distributed hybrids in 3D–MMIC technology

A multilayer branch-line coupler, rat-race hybrid and Wilkinson power divider are presented using 3D–MMIC technology with multiple BCB and metal layers on a GaAs substrate. The circuits are designed to operate in X-band and by using the lumped-distributed approach, together with highly miniaturised TFMS lines, these multilayer circuits have achieved as much as ten times size reduction in comparison to their conventional distributed form in microstrip. Techniques for compensating the unequal parasitic capacitance in asymmetrical MIM structures are described.

Three-port hybrid power dividers terminated in complex frequency-dependent impedances

A new CAD algorithm for design of two- and four-section three-port hybrid power dividers terminated with complex frequency dependent impedances is described. The dividers under consideration are composed of lumped element resistors and noncommensurate transmission line sections whose characteristic impedances take extreme, practically realizable, values. These values are assumed freely at the beginning of a design process. The validity of the presented design algorithm has been confirmed by numerical modeling and experimentation.

Radio-frequency connector and interconnect reliability in spaceborne applications

In addition to quality electronic components and subsystems, highly reliable interconnects are imperative in high-reliability applications such as spacecraft and satellites. System designers must therefore address and resolve issues related to the proper design and assembly process for connectors and interconnects for passive and active components. We have developed guidelines for the design of a space-qualifiable connector system based on our experience with defective hybrid couplers and power dividers, as well as our understanding of the material properties of the connector dielectric. We also discuss testing and the qualification of vendors of connectors and interconnects necessary to ensure high-reliability radio frequency and microwave components. >

N‐way sectorial hybrid power divider design using boundary element method (invited article)

AbstractA design method of an N‐way sectorial hybrid power divider is described, using the boundary element method (BEM). Scattering parameters and current density distribution on the sectorial part are obtained by BEM analysis. Isolation among output ports is much improved by putting a resistive slot in the sectorial part and resistive sheets between the adjacent output lines. The design method is verified by the six‐way power divider, which has been developed in our laboratory. © 1993 John Wiley & Sons, Inc.

A consideration on broadbanding of n‐way hybrid power dividers

AbstractA method is presented for broadbanding an n‐way power divider in which an absorbing resistor is used in one section. In the conventional Wilkinson power divider, it is known that the waves, equally reflected at the terminations, are absorbed by a resistor at the center frequency if a quarter‐wave line is connected to one of the output ports. To construct a 2n‐way power divider from a combination of these two‐way power dividers, 2n sections of lines are needed. In this paper, we constructed a network, which absorbs reflected waves, by connecting a 1/4‐wavelength section to an n‐way one‐section power divider if the characteristic impedance of the line and the absorbing resistor are optimized by numerical calculation. The circuit shown in the text has a broadband VSWR characteristic if attenuation of the transfer at the center frequency is permitted. The transmission characteristics then become flat, and the isolation characteristics are also improved.

Computer-based operant behavioral system for microwave bioeffects research.

For the investigation of the interaction of microwave radiation (MWR) with physiologic processes, a means of exposing a large number of animals to uniform and quantifiable MWR dose rates is desired. The design and characteristics of such a system for operant behavioral studies using rats is described. Individual irradiation chambers composed of probe terminated waveguide sections operating at 1.3 GHz are used. All of the 16 active chambers are driven in parallel from a single source via a modulation insensitive hybrid power divider. An additional group of 16 nonenergized chambers provide for parallel controls. Each of the chambers includes provision for presentation of visual discriminative stimulus, detection of operant response, and delivery of food reward. These behavioral components are managed by an 8 bit microprocessor that provides the necessary speed, reliability, and flexibility at low per unit cost. The input/output interface is described briefly and a typical program flow diagram for schedule controiled conditioning sessions is given. The irradiation/behavioral system represents a novel approach to the study of microwave induced alterations in operant behavior and demonstrates the practicability of adapting inexpensive microprocessor components to the management of large operant behavioral systems.

Theorems on Match and Isolation in Multiport Networks (Short Papers)

Two theorems on match and isolation among a number of ports of a multiport network are derived. Applications are given for n-way hybrid power dividers with matched and isolated output ports.

New n-Way Hybrid Power Dividers

A new n-way planar hybrid power divider (henceforth HPD) and an n-way coaxial-type HPD are proposed, and the synthesis methods of three-way and four-way planar HPD's are shown. As for the three-way planar HPD, the isolation characteristics among three ports show more than 20 dB, and the VSWR'S of four ports show less than 1.4 in 2:1 bandwidth. The experimental characteristics are in good agreement with the theoretical analysis.

A variable-coverage satellite antenna system

A multibeam antenna system and-combiner switch capable of producing a variable-coverage radiation pattern are described. The antenna consists of a waveguide lens illuminated by a 19-element feedhorn array. The combiner switch consists of a corporate arrangement of variable power dividers; the latter is made up of two phase shifters and two conventional hybrid power-dividers. An earth-coverage radiation pattern with less than 2-dB ripple and an antenna gain ≈ 20 dB is obtained by equally exciting all beams of the muItibeam antenna simultaneously. Excitation of a single feedhorn results in a narrow beam with an antenna gain ≈ 30 dB and a near-in sidelobe level less -20 dB. The side|obe level can be reduced appreciably by appropriately exciting the adjacent feedhorns. The frequency bandwidth corresponding to 0.5-dB decrease in antenna gain is 10 percent. A technique for computing the radiation properties of the antenna is described; the agreement with measured data is shown to be excellent.

Input VSWR and Output Isolation of Lossy N-Way Hybrid Power Dividers (Correspondence)

Input VSWR and Output Isolation of Lossy N-Way Hybrid Power Dividers (Correspondence)

Microwave components for wide-band phased arrays

The bandpass characteristic required for wide instantaneous bandwidth microwave components for phased arrays is described. One of the primary error considerations in the bandpass characteristic is the error effect on a compressed, frequency-chirped signal, the errors producing spurious time sidelobes and pulse broadening. Following this the design and performance of five types of microwave components or subsystems, operating over a 10 percent bandwidth, are discussed. These descriptions are of 1) tunnel diode amplifier, 2) microwave switching matrix, 3) subarray corporate feed, 4) ferrite phase shifter, and 5) time delayer for subarray steering. The tunnel diode amplifier (TDA) is of low-cost design, has 15 dB gain, 5.6 dB noise figure, and measurements of 100 amplifiers show standard deviations of insertion phase and gain of 5 degrees and 0.3 dB, respectively. The microwave switching matrix is constructed from ferrite, latching, TEM switches. A path through the matrix consists of 18 switches and has periodic gain and phase errors of 0.3 dB and 3 degrees, maximum. Path-to-path gain variations have a one sigma amplitude variation of 0.18 dB and a one sigma phase variation of 6.8 degrees. High-performance, low-cost ferrite switches were developed for the switching matrix and the nonreciprocal property of the switches has been shown to produce enhanced performance over reciprocal diode switches. The subarray corporate feed is of high-power waveguide-type construction and contains hybrid power dividers throughout to minimize reflection effects. The feed consists of two major subassemblies, each of which is entirely dip-brazed. The insertion phase and amplitude errors of the feed are 10 degrees and ±0.2 dB, maximum. The total insertion loss is 0.5 dB. The ferrite phase shifter is a wide-band design which will handle 65 kW peak power and 400 W average. The design employs a ferrite toroid in waveguide and the driver is analog and latching. The phase shifter has constant phase shift over the band; insertion loss is approximately 1.1 dB and is virtually free from higher-mode resonance loss peaks. Three system configuration of time delayers are considered. The design and performance of a 5-bit time delayer employing ferrite, latching TEM switches is described. The time delayer will handle an input power of 10 kW peak and 100 W average. Phase and amplitude errors through the time delayer are ±3 degrees and 0.5 dB, maximum.

Contraphaseshifter (Correspondence)

A novel combination of ring hybrid and variable power divider is shown to result in a three-terminal device having a single matched input and two outputs whose relative phase can be continuously varied independent of their amplitude.

N-Terminal Power Divider (Correspondence)

Recently Wilkinson has described an N-way hybrid power divider which decouples the outputs.