This letter presents a circular polarizer using multilayer frequency selective surface based on split rings bisected by metal strip. geometry provides the advantages of both low cross-polarization level and sensibility with respect to incidence angle ring-based topology. To validate proposed design, four-layer prototype operate in Ka-band has been designed, fabricated, tested. Experimental results show that axial ratios lower than 3 dB are obtained for angles as high 25 ° over range 25.5-36.5 GHz.

Reflective periodic arrays based on loaded ring slot resonators are analyzed. A full-wave mathematical model is developed and numerical results presented. It proven that the reflection angle for normally incident circularly polarized wave can be effectively controlled by proper positioning of reactive loads in resonators. Analysis characteristics Ka band one-layer reflectarray a conclusion redirected directions determined elevation angles as high 65/spl deg/ with conversion coefficient...

A new type of wideband dual-input hybrid Doherty outphasing power amplifier (HDO-PA) is developed in which the load-modulation scheme continuously converts as frequency increase, from previously reported HDO-PA mode with maximum flat efficiency response versus to conventional PA mode. For a symmetric implementation, this corresponds peak-to-backoff fundamental voltage ratio auxiliary linearly varying 9/7 2 frequency. transmission-line-based prototype first established at current-source...

This letter presents active dual-band frequency selective surfaces (AFSS) with close band spacing based on two switchable ring slots loaded by PIN diode switches. The response is achieved splitting the outer slot, and then shifting upward its fundamental resonance beyond of inner slot. proposed AFSS can provide four states operation including lower single-band, upper spacing, reflective mode. Experimental results waveguide simulator show that a ratio 1.14, insertion loss than 0.82 dB at...

An investigation of the periodic structure based on loaded ring slot resonators is presented. It shown that this can be used as a tunable frequency-selective surface. The possibility building an actively-switched surface also demonstrated.

Reconfigurable spiraphase-type reflectarrays based on ring slot resonators with switchable radial stubs are presented. The mathematical model of the infinite array was used to optimize element at 36.5 GHz. optimization goals were minimize dissipative loss in p-i-n diode switches and reduce cross-polarization radiation. finite then simulate radiation characteristics a reconfigurable reflectarray 277 optimized elements for different scanning elevation angles θ <sub...

This article presents the architecture and design methodology for a new type of dual-band Doherty power amplifier (DB-DPA), referred to as 3-Way DB-DPA, which consists main each band an auxiliary handling both bands. The DB-DPA improves average drain efficiency in concurrent operation compared traditional 2-Way by avoiding early clipping amplifiers, while benefiting from load—pulling (PA). improvement is verified theory simulation at current-source reference planes measurement with...

A novel frequency-agile power amplifier (PA) designed with a modified class-J theory enforcing constant maximum and minimum instantaneous drain voltages for all frequencies is presented. The resulting high-efficiency mode that requires reconfigurable supply exhibits clockwise fundamental- second-harmonic load impedance trajectories versus frequency facilitating the PA design. This clockwise-loaded (CLCJ) enables capability enhanced efficiency when proper voltage codesigned fundamental...

An active ring slot resonator loaded by switchable radial stubs is investigated.It shown that this element can be used as the unit cell of a reconfigurable frequency selective surface (RFSS).Equivalent circuit and full-wave mathematical models are obtained to evaluate reflection characteristics RFSS based on element.The possibility obtain different resonant transmission frequencies discussed.The model developed design an X band capable obtaining at 9.65, 10.28, 10.83 12.05 GHz.Commercially...

Summary As wireless cellular communication keeps expanding toward higher bandwidth, multiband signals, and high frequencies of operation, the design power efficient radio frequency amplifiers (PAs) for phone basestations is submitted to more stringent requirements. This paper discusses promising technique nonlinear embedding, which may help stream line such PAs. To this order, a GaN PA from device modeling circuit presented. The large signal high‐electron‐mobility transistors including...

In this paper, reflective periodic arrays with rotating spiraphase-type elements based on loaded split rings are analyzed. It is proven that these can be reconfigured over a wide frequency band high reflection elevation angles, low conversion losses, and axial ratios. A full-wave mathematical model has been developed to calculate their characteristics. This used design Ka-band reflectarray. The analysis of the designed reflectarray shows an incident circularly polarized wave redirected at...

This work introduces a novel design theory for single-input hybrid Doherty power amplifier (PA) inspired by the space existing within previously reported dual-input Doherty–Chireix (outphasing) continuum. Unlike conventional <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\lambda /4$ </tex-math></inline-formula> PA inverter which only performs correct load modulation at its center frequency, (HD...

A periodic structure based on shorted ring slots is investigated. It shown that this can be used as an adjustable frequency-selective surface. The possibility of adjusting the resonant frequency over more than octave band demonstrated.

<para xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> The design and performance of a 2-bit p-i-n diode reflective &lt;formula&gt; &lt;tex&gt;$X$&lt;/tex&gt;&lt;/formula&gt;-band phase shifter are described. This uses the spiraphase principle changing. Benzocyclobutene-based bias circuits used to decrease insertion loss level reduce fabrication costs. It has been proven that demonstrates better than 0.5 dB in frequency band from 9.75 11.5 GHz for...

An optimal three-harmonic definition of class F at the intrinsic level is presented for realistic transistor models exhibiting IV characteristics with a nonzero knee voltage. This updated class-F needed use recently reported embedding device model, which predicts in single harmonic balance simulation voltage and current waveforms required package reference planes to sustain an mode operation. Optimal operation obtained by setting infinite third-harmonic output impedance instead using open...

A tri‐band frequency selective surface (FSS) with close band spacing based on split ring slots for y ‐polarised incident waves is investigated. The response obtained by reducing the strong mutual coupling between closely packed concentric rings through splitting and redistributing location of currents at resonances. To validate proposed FSS, a Ka FSS was designed, fabricated tested. Experimental results showed spaced resonances 27.3, 31.7 36.2 GHz. Frequency ratios 1.16 second to first...

This letter presents a dual-frequency reflectarray (RA). RA is capable of forming two differently oriented main lobes with the same sense circular polarization in directions determined by reflection elevation angles θ <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">01</sub> and xmlns:xlink="http://www.w3.org/1999/xlink">02</sub> at closely spaced frequencies. The element contains pair concentric split-ring slots different angular rotations....

A cascaded circular‐polarisation‐selective surface (CPSS) based on bisected split rings is presented. The proposed CPSS allows the transmission of one sense circular polarisation while reflecting other sense. To validate design, a nine‐layer prototype that operates in Ka band has been designed, fabricated and tested. Experimental results show coefficients higher than −1 dB axial ratios lower 3 are obtained for polarisation, whereas −20 opposite over frequency from 26.39 to 35.43 GHz.

This paper presents a spiraphase-type reflectarray based on reactively loaded ring slot resonators. The infinite array approach was used to optimize the unit cell geometry obtain high aperture efficiencies and low cross-polarization levels at large reflection elevation angles $\theta_0$ . results of optimization were design four 367-element reflectarrays for 0°, 20°, 40°, 60° operating 36.5 GHz. designed then fabricated tested. experimental investigation revealed that 0.60, 0.51, 0.42, 0.21...

Monolithic integration of loading capacitors into the X-band frequency selective surfaces (FSSs) based on ring slots is investigated as a means to control response FSS. Ring and integrated are formed microwave-friendly substrate using multistep thin-film deposition patterning. Numerical simulations experimental measurements performed extract capacitance values quality factors fabricated capacitors. It proven that these in range 0–120 fF shift congruently resonant slot FSS from 11.8 8.14 GHz....

In this paper, a dual circularly-polarized multilayer reflective surface (MRS) based on loaded ring-slots for reflectarray applications is presented. The MRS comprises wideband circular polarizer cascaded with screen independent phase shifting properties the two orthogonal linearly polarized components. first polarization conversion accomplished by four-layer periodic arrays of bisected split rings that converts incident waves, one left-handed (LHCPW) and other right-handed (RHCPW), into...

This paper presents a polarization insensitive frequency selective surface (FSS) based on concentric ring slots with five closely spaced passbands. The proposed FSS unit cell contains coupled supplementary innermost slot. close band response within the first transmission bands is achieved by influence of modified geometry obtained inclusion sixth added slot causes appearance stopband, due to conductive between fifth and apertures, passband produced inherently aperture. effect additional...

Reflective arrays based on shorted ring slots are analyzed. It is proven that reflection angle for the normally incident circularly polarized wave can be effectively changed by proper situation of conductive shorts. Thus, phased with wide-angle scanning built using slots.

A quasi-optical beam steering multilayer lens with scanning in E -plane is analyzed. full-wave mathematical model developed to predict the characteristics of lens. The used optimize performance a three-bit It demonstrated that calculated conversion coefficients for optimized are better than -2.1 dB frequency band from 27.5 32.5 GHz transmission elevation angles up 28°. two-bit corrects phase front at aperture short .E-plane sectoral horn has been designed, fabricated and tested verify model....