Description:Field of Invention
Antennas have been the subject of intense study attention for many years due to their importance as components of wireless communication systems. A well-performing antenna can always help to simplify the architecture of the communication system as a whole and increase the quality of the final transmission. In order to achieve intriguing antenna characteristics, an increasing number of antennas based on different structures inspired by metamaterials have been constructed and studied in the last ten years. This is because artificial electromagnetic metamaterial constructions have unique and fascinating properties, such simultaneous negative permeability and permittivity. Two well-known subfields of resonant antennas (RAs) and leaky wave antennas (LWAs), two antennas inspired by metamaterials, have attracted a lot of interest from researchers. The artificial electromagnetic metamaterial structure and antenna design may allow the RA or LWA. It appears that research into artificial electromagnetic metamaterial structures and their uses is still ongoing, with a lot of potential and benefits to be investigated further. Antenna performance, including gain, polarization, radiation pattern, and frequency response, can be improved with novel artificial electromagnetic metamaterial structures-based antenna designs.Because of the potential gains in antenna performance, An important and fascinating area of research includes antenna designs with distinct antenna properties that are based on innovative metamaterial structures for artificial electromagnetic.
Objectives of the invention
Research on artificial electromagnetic metamaterial structures and applications seems to be ongoing, with a great deal of promise and advantages to be looked into this more. Novel artificial electromagnetic metamaterial structures-based Enhancements in gain, polarization, radiation pattern, and frequency response are possible with certain antenna designs. Because of the potential improvements in antenna performance, antenna designs based on novel artificial electromagnetism metamaterial structures with distinctive antenna characteristics represent an important and exciting area of research. One potential application could be a monopole antenna that is inspired by metamaterials and is loaded with a single CRLH unit cell. Enhancements in gain, polarization, radiation pattern, and frequency response are possible with certain antenna designs. Because of the potential improvements in antenna performance, antenna designs based on novel artificial electromagnetism metamaterial structures with distinctive antenna characteristics represent an important and exciting area of research. One potential application could be a monopole antenna that is inspired by metamaterials and is loaded with a single CRLH unit cell.
The objective is to study the antenna properties of the metamaterial ECRLH structures and develop RAs and LWAs based on them, taking into account the ECRLH structure's underlying theory. to design dual-passband LWAs around two supercell structures inspired by metamaterials, enabling them to perform backward-to-forward leaky-wave radiation in both pass bands. An electrically tunable LWA is to be constructed using discrete ferroelectric (FE) barium strontium titanium (BST) thin-film varactors. Furthermore, more analysis needs to be done on the uncertainty in the BST permittivity determination from the characterisation process.
Background of the invention
Typically, a LWA design starts features a wave-guiding framework that allows some power to escape as the wave travels. Based on their structural forms (i.e., 1-D or 2-D) 11 and excitation locations (i.e., end excitation or center excitation), the LWAs can attain a variety of leaky-wave characteristics [D. R. Smith]. A guided wave's energy passes through a LWA's guiding structure, and any branches that cause disruptions will stop the wave from propagating smoothly along this guiding structure. For leaky-wave applications, the energy can primarily radiate or leak at these disturbance branches from the guiding structure. One conceivable outcome of energy radiation from periodic or uniform perturbation branches is a sharply focused fan beam. Because of its unique feature of varying primary beam direction with frequency, the LWA is suitable for high-directivity applications.
The complex propagation constant ?? = ?? + ???? [R. W. Ziolkowski], for a LWA, determines its leaky-wave radiation. Here, ?? stands for attenuation constant and ?? for phase constant. Notably, the main beam width, radiation efficiency, and radiation angle of a leaky-wave structure can all be determined by these two crucial factors, ?? and ??, respectively. Generally speaking, the radiated power of a guiding structure decreases exponentially from its beginning to its end. A higher ?? can lead to a broader beam width and, in terms of the power attenuation or leakage parameter, a shorter effective aperture with less power leakage for radiation [R. W. Ziolkowski]. On the other hand, a smaller ?? might lead to a longer effective aperture and a narrower beam width, which would result in more radiation power loss [R. W. Ziolkowski]. Generally speaking, a LWA should be built to attain about 90% of the allowable power along its guiding structure when the wave reaches the antenna end. [R. W. Ziolkowski]. The residual power can be completely absorbed if the guiding structure has a corresponding load at its end. As the operating frequency varies, the phase constant ?? also alters, potentially leading to a shift in the beam direction.
There are frequently two values that describe permittivity that is depending on the electric field.A quantity's complex expression is er = er' - jer''. The energy stored in the dielectric medium is known as er', or the actual complicated permittivity component. It is also known as relative permittivity or the dielectric constant. On the other hand, the energy dissipated in the dielectric medium is represented by the imaginary component of complex permittivity, or er''.

Description of Prior Art
A satellite-borne multi-band integrated receiving antenna is described in this invention. It consists of an L-band multi-beam antenna array, a VHF-band antenna array, a base, an L-band antenna fixing base, and an integrated receiver. The L-band multi-beam antenna array and the VHF-band antenna array are connected by a cable, and the integrated receiver and the L-band antenna fixing seat are fixed at the center of the base's top surface. The cross sections of the base and the L-band antenna fixing base are both positive N and positive M polygons with alpha inclination on each side. The L-band multi-beam antenna array is set up on the L-band antenna fixing base. The L frequency band antenna can simultaneously generate a plurality of beams to cover a monitoring area; the entire antenna is telescopic; the folded antenna envelope is small; the small satellite platform is easy to mount; and, once the antenna is transmitted into orbit, a dual-system simultaneous high-performance receiving process is realized by a flexible unfolding mechanical mechanism. The VHF frequency band antenna can meet the requirement of blind separation of a plurality of collision signals by adopting an array. [CN114421117A]

An antenna for wireless communication can consist of a radiating element coupled to the feed element, a carrying structure-provided ground plane, and a feed element. The radiating element is positioned roughly parallel to the feed and shortening elements and vertically displaced from the ground plane. The antenna may also incorporate a parasitic element that is directly mounted on the carrying structure and forms part of the ground layer of the carrying structure. [US7821470B2].
The current invention is related to microwave antennas, specifically to planar antenna designs for transmitting and receiving that have an omnidirectional radiation pattern for applications requiring ultra-wideband (UWB) technology. The objective is to provide a planar antenna design for a wireless wideband (UWB) system that can handle symmetrical Omni-directional transmitting and receiving signals, transmit and receive microwave signals in the UWB frequency band, and reduce costs significantly by applying antenna layout prints in tandem with the production of traditional radio frequency (RF) front-end chip circuits.The components of the antenna apparatus that resolves this issue are a feeding device that can supply signals to and from the radiator device, a ground plane device that can reflect electromagnetic waves transmitted and/or received by the radiator device, and at least one radiator device that can transmit and/or receive electromagnetic waves in ultra-wideband technology. With the radiator device tapering towards the ground plane device, both the ground plane and the radiator device are planar on the same plane and aligned along a single symmetry axis. [US7545339B2].

Summary of Invention
Applications to antenna designs include BST materials and a few tunable approaches. There is room for improvement in the majority of current antenna designs that rely on artificial electromagnetic structures. These improvements could include multiband leaky-wave radiation characteristics, radiation enhancement, and bandwidth augmentation. Because of their advantages at microwave frequencies, BST materials—which are also common tunable materials—allow antenna designs to be reconfigurable in terms of frequency or pattern. Furthermore, a review and comparison are conducted of the literature pertaining to current antenna designs that employ alternative tuning approaches, such as silicon varactors, liquid crystals, and MEMS switches. Nevertheless, these antennas have certain drawbacks, like the RA designs' limited number of working resonances, the CRLH-based LWAs' single passband, and the multiband LWA's non-frequency-or non-pattern-reconfigurable designs. A class of open-ended RAs for multiband or frequency-agile applications is given, based on a single ECRLH unit cell structure. Using a brief micro strip feeding line as an excitation source, the RAs can produce numerous operating resonances. Multiband properties can be achieved by the passive RAs. Furthermore, one conventional monopole antenna taking up a comparable amount of space is not as frequency-sensitive as one functioning resonance of the passive RA with IDSs. The objective of an electronically tunable RA using a single semiconductor varactor is to preserve the wideband coverage generated by the other operational resonances over 1.7-6.0 GHz while achieving frequency tunability over 0.7-0.96 GHz via one operating resonance at the low frequency. The Chip section's research on resonance control in the RA structures served as the foundation for this design. It has been established that a LWA based on the CRLH structure can be electronically tweaked using discrete FE BST interdigital varactors. Discrete BST varactors in the LWA structure lower BST material losses, which can enhance antenna radiation performance. Moreover, the uncertainty analysis of the BST material is investigated using the conformal mapping method.
Using a series of CST simulations, the uncertainty in the expected frequency of the balance point, gain, etc., may then be determined. Perhaps the uncertainty in e' can be used to compute the uncertainty in the capacitance values of BST_varactor_1 and BST_varactor_2. The essay examined the antenna's response to the "worst-case" value of er'. Through an awareness of these limitations, one can ascertain whether the manufactured antenna performs as well as can be expected given the reliability of the input data, or whether a design can be produced with a high yield in practice. It's possible that the antenna was made using dubious practices if things end up being worse than you expected.
Inspired by metamaterials, RAs and LWAs have been introduced for multiband or frequency-agile applications. Based on a single ECRHL unit cell architecture, the open-ended RAs acquire the multiband or frequency tunable features. The micro strip LWAs achieve the CRLH leaky-wave qualities in both passbands, based on the metamaterial-inspired structures (Supercell_v1 and Supercell_v2). These architectures provide dual-passband functionality.
Using an electronically tunable LWA based on the Supercell_v2 structure, it is possible to maintain the backward-to-forward leaky-wave radiation characteristics within the high passband and relatively independently control the low balanced point while maintaining the frequency position of the high balanced point. Moreover, simulations have demonstrated the feasibility of a micro strip LWA with discrete BST variables. Due to their potential to produce numerous functioning resonances at certain frequencies, these resonance antennas (RAs) are an extension of conventional metamaterial-inspired RAs. The passive RAs' IDSs and chip capacitors allow for multiband functionality and support a variety of wireless frequency bands, ranging from 0.5 to 6.0 GHz.An electronically tunable RA with a single semiconductor varactor can achieve the low frequency tunability of one operating resonance without sacrificing the broad band coverage produced by the other operating resonances. With so much potential, this class of RAs can serve as a valuable reference for the design of small antennas intended for multiband applications. The uncertainty ratios establish a relationship between the geometric parameter standard deviations and the BST permittivity uncertainty. Furthermore, the uncertainty ratios at various frequencies remain unchanged. The LWA design with discrete BST varactors is one workable way to combine the antenna construction with BST materials. Furthermore, the uncertainty analysis of the BST permittivity can provide useful guidance for the construction of a BST-based antenna. We can infer which geometric parameters influence the BST permittivity from the analytical results.
Detailed description of the invention
An intriguing subset of resonant antennas are those inspired by metamaterials. Antennas in this category can use their intrinsic resonant modes to generate one or more operating resonances for radiation when properly excited. The majority of RAs in use today are created using metamaterial structures, particularly the CRLH structure. The CRLH structure served as the model for this RA's design. This antenna uses four cascading micro strip-based CRLH unit cells as its resonant structure. Every unit cell is equipped with a shunt meander line that connects to a rectangular patch and an interdigital capacitor (IDC). [K. Aydin]. There is a virtual ground plane (GP) model for each rectangle patch. Figure 1 depicts this antenna's configuration. This antenna's intrinsic resonant modes, such as the zeroth-order mode, can produce many operating resonances when stimulated through a micro strip line, allowing it to function at various frequencies. At 4.88 GHz, There is activity in the zeroth-order mode (?? = 0) resonance. The resonance frequencies originating from the negative-order modes (??< 0) resonances surpass the ZOR resonant frequency, while the positive-order modes (??> 0) resonances function above it.
This antenna is constructed using a planar CRLH unit cell configuration. This antenna supports the zeroth-order mode resonance of the radiation and shows wideband characteristics. With the zeroth-order mode (?? = 0) resonance at 2.24 GHz and the first-negative-order mode (?? = -1) resonance at 1.99 GHz, this CRLH-based RA provides a broad coverage from 1.9 GHz to 2.35 GHz by combining. This method of increasing bandwidth can be thought of as a useful way to improve the bandwidth of antenna designs for mobile devices. On display is a tiny ZOR antenna with two CRLH unit cells set up in a cascade. The front and rear view variants of this antenna are also shown in Figure 3.5. This antenna configuration uses two asymmetrical straight meta-strip lines with via-holes, metal-insulator-metal (MIM) parallel-plate capacitors, and the gap capacitor between unit cells to replicate the shunt inductors, series capacitances, and shunt capacitances, respectively. This allows for improved impedance matching and increased antenna efficiency. This ZOR antenna's zeroth-order mode (?? = 0) resonance frequency is 2.3 GHz. It has a linear polarization and a 2.3 dB higher peak gain. Its efficiency is 79%. Based on the CRLH structure, this dual-band ZOR antenna is intended for small-sized multiband smart phone applications. The recommended antenna arrangement is shown in Figure 2. This proposed antenna can generate dual bands by stimulating a monopole antenna with two parasitic metal-strip components connected to the GP in separate dimensions. It does this by employing the proper radiation to induce the zeroth-order mode (?? = 0) resonances of two CRLH unit cells. The anticipated antenna gain for this antenna is 0.09 dBi at 0.9 GHz and 2.0 GHz, respectively. Thus, this antenna can be used for GSM850/900 (824-960 MHz) and DCS1800/PCS1900/UTMS (1710-2170 MHz) mobile device applications. This antenna design has a lot of potential applications in wireless mobile terminals in the future.
SMD chip capacitors are used in the construction of a micro strip LWA based on the ECRLH structure. Rogers RT/duroid 5880, with a thickness of 1.575 mm, dielectric constant of 2.2, and loss tangent of 0.0009, is the substrate material. There are fourteen cascaded ECRLH unit cells that make up the ECRLH TL structure. Figure 5.3 displays the arrangement of a single ECRLH unit cell structure. The SMD MURATA 0402 chip capacitors in this unit cell design realize Cvs, Cvp, Chs, and 20 pF, 4.1 pF, 1.5 pF, and 0.1 pF, in that order. It shows how a center bandgap divides the formation of two distinct passbands at the high and low frequencies."Low passband" and "high passband," respectively, are the names given to these two passbands at low and high frequencies. The low passband spans 0.6-1.55 GHz and the high passband spans 3.1-6.5 GHz in the -6 dB bandwidth.
The waves reflected from the metal and magnetic conductor components are out of phase when a plane wave impacts a bi-reflectional ground plane. The surface impedance is a single quantity that can be used to characterize the surface behavior of electric and magnetic conductors. This also holds true for textured surfaces in realistic designs as long as the effective model condition—that is, the structure's period being much less than its wavelength—is met. Surface impedance is the ratio of the electric field to the magnetic field at the surface. A magnetic conductor has a very high surface impedance in contrast to the low impedance of a smooth electric conductor surface.
The bi-reflectional ground plane has been modeled using two alternative situations. A magnetic conductor surrounds an electric conductor plane in the first model, but in the second, the opposite is true—a magnetic conductor surrounds an electric conductor plane. These scenarios were modeled using ANSYS HFSS software. To put it simply, the electric conductor is modeled using the Perfect-E boundary condition. Nonetheless, a planar perfect conductor coated by Perfect-H is needed to simulate the magnetic conductor. A boundary condition is established. In this case, The Perfect-H boundary condition states that the tangential component of the H-field is zero and that the incident wave is reflected by the perfect conductor. As a result, the tangential component of the magnetic field for both the incident and reflected waves must be constant.
Subsequently, a dipole antenna was positioned ?? above the bi-reflectional plane's surface. The dipole was intended to operate at a frequency of 15 ??????, and the bi-reflectional ground plane's overall size was specified at 33.6???? × 33.6????. Using a GA optimization method, the electric and magnetic conductors' size and distance ?? were optimized to increase the concentration of reflected waves above the bi-reflectional plane's center. A regular PE ground plane yielded a maximum gain of 7.84 ??????, but the bi-reflectional ground plane produced a peak gain of up to 11.55 ??????.
We further explore the characteristics of the high and low passbands of this LWA's leaky-wave radiation. Figure 5 displays the computed and observed normalized co-polarized farfield leaky-wave radiation patterns in the XOZ plane of this LWA inside the two passbands. The principal beam scan within the low passband, covering 0.9-1.25 GHz and ranging from -42° to +36°, is displayed.in Figure 5(a). The high passband's farfield leaky-wave radiation properties, however, differ from those of the low passband. Leaky-wave radiation in the forward (RH band) occurs in the high passband's low-edge region, whereas leaky-wave radiation in the backward (LH band) occurs in the high-edge region. Figures 5(b) and 5.6(c) display, within the high passband, the co-polarized normalized farfield leaky-wave radiation patterns as measured and as simulated, respectively. As shown in Figure 5(b), the leaky-wave radiation from this antenna spans the low edge of the high passband, or 3.1–3.6 GHz, with a range of +12° to +60°. The primary beam in Figure 5(c) scans from -80° to -24° at the high border of the high passband throughout a frequency range of 5.7–6.2 GHz. In the broadside with the high passband, the change from the backward to the forward orientation is not seamless.
It is feasible to evaluate the losses caused by the BST materials used in the LWA construction by comparing the lossy and lossless scenarios. The simulated gains of LWA with the lossless BST materials under the 0 V condition are displayed in the first lossless scenario, where the loss tangent of the BST films is set to zero, i.e., V0 = 0. The simulated gains with the entire set of lossless varactors under the 0 V DC bias voltages are obtained in the second lossless scenario, where the varactors are considered to be lossless. Gain differences of about 0.5-0.8 dBi for the first lossless case and 0.9-2.3 dBi for the second lossless case are observed when comparing the simulated gains. The LWA radiation performance is negatively impacted by the BST materials used in the antenna construction by about 0.5–0.8 dBi of gain deterioration, while all of the varactors contribute roughly 0.9–2.3 dBi.
Brief description of Drawing
Figure 1: It depicts this antenna's configuration. This antenna's intrinsic resonant modes, such as the zeroth-order mode, can produce many operating resonances when stimulated through a micro strip line, allowing it to function at various frequencies.
Figure 2:This displays the recommended antenna's configuration. By stimulating a monopole antenna with two parasitic metal-strip components connected to the GP with various dimensions, this proposed antenna may yield dual bands. It accomplishes this by using appropriate radiation to cause two CRLH unit cells to resonate in the zeroth-order mode (?? = 0).
Figure 3 :This image shows a constructed LWA with 14 ECRLH unit cells that are cascading. The overall length of this LWA is 280.4 mm, with a width of 50 mm.
Figure 4: It displays the observed and simulated outcomes of this LWA's S11 and S21.
Figure 5:Co-polarized far-field leaky-wave radiation patterns, standardized by simulation and experiment at the XOZ plane, inside two passbands: (a) 0.9-1.25 GHz; (b) 3.1-3.6 GHz; and (c) 5.7-6.2 GHz. , Claims:The scope of the invention is defined by the following claims:

Claims:
1. The metamaterial-inspired structures for improved antenna properties comprising,

a) The chip capacitors and IDSs, the passive RAs are used to accommodate a variety of wireless frequency bands between 0.5 and 6.0 GHz and achieve multiband characteristics.

b) A LWAs based metamaterial-inspired Supercell_v1 and Supercell_v2 structures have been used to realize the backward-to-forward leaky-wave radiation capabilities inside both passbands.

2. As claimed in Claim 1, the backward-to-forward leaky-wave radiation characteristics are not realized in the high passband of the suggested LWA, which is based on the ECRLH structure.

3. As claimed in Claim 1, to ascertain the FE BST permittivity, an uncertainty analysis was carried out, considering the significance of the BST permittivity for tunable antenna designs.