A frequency-diverse bunching metasurface antenna (FDBMA) that can be used for microwave computational imaging (MCI) systems is proposed in this article. The FDBMA generate low-correlated radiation patterns with a reduced frequency interval of 20 MHz and angle <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$45\mathrm {^{\circ }}$ </tex-math></inline-formula> from 32 to 36 GHz. by combining disordered cavity...

In this article, a compact ultra-wideband balanced filtering power divider (FPD) with controllable cut-off frequencies is proposed based on the spoof surface plasmon polaritons (SSPPs). Firstly, SSPP unit cell designed using I-shaped microstrip structure for size miniaturization, and dispersion characteristics are analyzed. Next, highpass (PD) high common mode (CM) suppression level microstrip-to-slotline (MTS) transition feeding T-shaped slotline structure. A differential (DM) response CM...

Correlations and mutual couplings in antenna arrays lead to performance deterioration of multiple-input-multiple-output (MIMO) systems. The relation between coupling correlation is complex, especially non-isotropic multipath environments. Reducing does not guarantee an eventual reduction the overall vice versa. In general, it a trivial task reduce simultaneously arbitrary this correspondence, planar metamaterial structure (PMS) array-antenna decoupling surface (ADS) are applied array for...

In order to solve the low signal-to-noise ratio (SNR) problem of differential coincidence imaging (DCI) system, a frequency-diverse metacavity Cassegrain antenna (FDMCA) that is able generate low-correlated bunching radiation patterns proposed in this communication. The FDMCA designed according form, which consists half-spherical etched with backprojecting slot arrays and parabolic reflector. total, 81 useful measurement modes angle 40° are obtained from 32 36 GHz. First, field distributions...

The performance of a scalar computational imaging system is inherently influenced by the target's geometrical features. Nevertheless, leveraging polarimetric information enables robust target image reconstruction, which can overcome limitations imposed varying In this paper, metamaterial iris-based cavity antenna (MCA) that generate dual-polarized spatially-random illuminating patterns from 75 to 110 GHz proposed. developed MCA composed square with irregular boundaries and lid etched...

Polarimetric information is beneficial for enhancing the imaging quality of computational systems. However, hardware that can extract polarimetric in a (CPI) system remains heavily unstudied. Thus, this paper, hyperuniform frequency-diverse metacavity transceiver (HFDMT) capable retrieving throughout K-band proposed. The proposed HFDMT etched with cross-shaped irises arranged distribution. transmitter and receiver conventional CPI are replaced by two isolated ports HFDMT, which significantly...

A frequency-diverse bunching metamaterial antenna for coincidence imaging in the Ka band is proposed this paper. The includes a broadband circular array and metalens. Firstly, order to enhance characteristic, designed based on 60-degree beamwidth design generate radiation patterns from 32 GHz 36 GHz. Then, types of elements with different transmission phases are selected form metalens random distribution gradient zoom coefficient design. Moreover, constituted by loading array, which can less...

A wideband frequency-polarization-diverse reflection aperture (WFPRA) for coincidence imaging is proposed in this letter. The composed of polarization sensitive metamaterial cells with different resonant frequencies and rotation directions. cross-polarization information can also be used to generate test modes (uncorrelated spatial gain distributions) based on the conversion basic cell WFPRA. number uncorrelated significantly increased compared traditional case only one statistical dimension...

In this paper, metasurfaces with both cross-polarization conversion and vortex beam-generating are proposed. The proposed finite metasurface designs able to change the polarization of incident electromagnetic (EM) waves its cross-polarization. addition, they also can modulate incidences into beams carrying orbital angular momentum (OAM) different orders ( l = + 1 , 2 − ) by applying corresponding transmission phase distribution schemes on aperture. generated at 5.14 GHz. loss is lower than...

In this letter, a frequency-diverse transmission metamaterial aperture (FDTMA) with bunching random beam (BRB) is proposed for coincidence imaging. The FDTMA consists of modulation lens and broadband microstrip patch antenna array, which used as feed source. First, an equivalent medium containing both dielectric layer structure modeled analyzed using the electromagnetic theory. zoom coefficients elements are to simplify design aperture. Then, basic designed based on model. Moreover,...

In this paper, the design of a computational microwave imaging (CMI) oriented frequency-diverse reflection metasurface antenna (FDRMA) is presented. Designing FDRMA for CMI requires careful synthesis framework, from topology metamaterial elements to statistical analyses and evaluation its performance. Consequently, we begin with an investigation different element topologies aim choose optimal one constitute desired metasurface. The then designed by randomly distributing diverse structural...

A dual-polarized frequency-diverse metaimager (DFM) applicable for computational polarimetric imaging (CPI) is proposed in this paper. The DFM working from 18 to 22 GHz can generate spatially-random measurement modes at different operating frequencies as well under varying polarization states. a low-profile metacavity etched with sparsely arrayed cross-shaped slots. Firstly, high-dispersion random metasurface consisting of 100 kinds elements designed the realization field distributions...

A near-field (NF) measurement method stemming from the microwave computational imaging (MCI) concept is proposed in this letter.In an MCI system, sensing matrix comprises radiated fields of both transmitter and receiver.We demonstrate that, with apriori knowledge antenna radiating quasi-random patterns tailored for MCI, allows calculation NF distribution antenna-under-test (AUT).The technique follows a twostep process.First, system fixed calibration targets directly predicted backscattered...

A frequency-diverse metasurface antenna with hybrid bunching methods for coincidence imaging is proposed in this paper. The contains an excitation system, a and double-layer-metal-plate system. Firstly, the system of divided into two parts, bunching-excitation module random-excitation module. includes seven-element coherent array that can generate beams 80 degree beamwidth from 32GHz to 36GHz; eight elements distributed evenly excite same working bandwidth. multilayer feed also designed...

A frequency-diverse metamaterial cavity antenna (FDMCA) that can be used for the microwave coincidence imaging is proposed in this letter. The FDMCA a slot array excited by metamaterial-based cavity, which generate diverse radiation patterns at different frequencies. average electric-field variation (AEV) introduced to forecast correlation coefficients of generated antenna. lower are, better quality reconstructed image is. To verify validity AEV and superiority FDMCA,...

The multi-mode orbital angular momentum (OAM) beams can be effectively applied in target detection when the divergence angles are equal. resolution threshold of coincidence imaging system with OAM is analyzed assisted by subspace projection method. First, relationship between and correlation function (CF) measurement mode obtained based on first-order algorithm for OAM-based (MM-OAMCI). Then, feature vector each unit extracted to distinguish point discretized plane. Finally, given three...

A novel coincidence imaging method using the differential of radiation patterns (DRP) generated by a frequency diverse aperture (FDA) is proposed in this letter. The FDA consists metamaterial structure cells with different resonance frequencies double layers and wideband patch antenna. minimum correlation coefficient criterion DRP used during location design cells. transmitting receiving channels at each should be separately calibrated advance to obtain grouped balanced DRPs. In addition,...

This paper proposes a broadband metamaterial aperture antenna (BMAA) with large capacity, low correlation coefficients and high radiation efficiency for coincidence imaging in the terahertz band. The BMAA consists of random modulated stripline structure as feed system. Firstly, element complementary electric-inductor-capacitor (cELC) is designed formed via randomly-distributed elements different resonant frequencies. By leveraging amplitude phase modulation characteristics elements, can...

A frequency-polarization sensitive metasurface antenna (FPSMA) that can generate low-correlated measurement modes both at different working frequencies and under polarization statuses is proposed in this letter. The FPSMA composed of a linearly polarized patch as the excitation module modulation module. capacity enlarged significantly due to introducing domain. domain refers angle between direction metasurface. Performances FPSMA, including reflection coefficient, radiation efficiency,...

Nowadays, there is no good scheme for simultaneously achieving super-resolution imaging within a coherent beamwidth and beam scanning in microwave radar. In this paper, synthetic method based on randomly excited antenna array, which possesses the ability of coincidence imaging, proposed. The array comparable to that conventional phased with same size, its steering angle can be adjusted by modulating excitation signals. Firstly, optimized covariance matrix proposed uniformly bunch spatial...

A frequency-polarization-port-diverse (FPPD) cavity imager with bunching random beams working in the W-band (from 76 GHz to 81 GHz) is proposed this paper. random-coherent-superposition design method utilized beam. Low-correlated radiation patterns can be generated when excited either at different frequencies or by ports. Orthogonal polarized also vary from each other, which enlarge measurement modes polarization dimension. The FPPD composed of a disordered cavity, lid etched elliptical...

Abstract Traditional multi-mode orbital angular momentum (OAM) beams suffer from low energy efficiency in detection since the divergence angle tends to increase with increasing order of OAM mode. Thus, equal are highly desirable. In this paper, a frequency-diverse (FDMM) modulator approximately is proposed. The composed an modulation metasurface and spatial filter (SF) narrow passband. Firstly, designed based on multiple ring-like regions different radii aperture. Each mode beam generated at...

A disordered-cavity-based metaimager (DCM) that can be used for coincidence imaging is proposed in this letter. The DCM possesses narrow frequency gap, low correlation coefficients, and high efficiency. Due to the all-in-one design, has good robustness insensitive fabrication errors, which suitable fabricated using 3-D printing technique. working from 32 36 GHz contains a disordered cavity, sets of high-efficiency coupling slots frequency-diverse metasurface. Measurement modes generated by...

In this paper, three types of stirrers are analyzed and compared in terms the field uniformity a reverberation chamber (RC). The first type (i.e., Type I) is standard Z-type rotating mode stirrer consisting four metal plates. second II) similar to stirrer, yet with two plates clockwise other counterclockwise. third III) translating rectangular plate. For fair comparison, we make sure that volumes swept by same. used compare performances stirrers. Then, comparison stirrers' carried out get...