Query: Input impedance of microstrip slot antennas

title: Input impedance of microstrip slot antennas
abstract: A theoretical and experimental study of the input impedance of microstrip fed radiating slots is presented. The agreement between theory and laboratory measurements (performed at X, S, and UHF frequency bands) shows that the developed theory can be used for the design of microstrip slot antennas and slot arrays.

title: Input impedance of microstrip slot coupled dielectric resonator antennas mounted on thin dielectric layers

title: A simple technique for evaluation of input impedance of microstrip fed slot antennas
abstract: A simple technique based on the transmission line model is introduced for the evaluation of the input impedance of the microstrip fed slot antenna. The equivalent circuit of the antenna is presented and methods for the determination of its components are discussed. The validity of the technique was supported by experiments.

title: Variations Of Wide Band E shape And U slot Cut Rectangular Microstrip Antennas
abstract: Wide band designs of E shape and U slot cut Rectangular Microstrip antennas are discussed which yields bandwidth of 207 (23% and 174 (19% MHz, respectively. For further bandwidth enhancement, various designs of E shape and U slot cut rectangular patch antenna with tapered patch width are proposed. Tapering in patch width alters the input impedance at TM10 mode in E shape patch and at TM10 and TM02 modes in U slot cut rectangular patch that yields increase in the bandwidth. Tapered design of E shape patch gives bandwidth of 225 MHz ~26% and that of U slot cut patch yields bandwidth of 202 MHz ~22% In another tapered width design of E and U slot cut RMSAs, patch width is reduced at both the ends and these designs yields bandwidth of above 270 MHz (29% and 212 MHz (22.2% respectively. The varying width patches exhibit broadside radiation pattern with moderate increment in the values of broadside antenna gain.

title: An analysis method for the input impedance and mutual coupling of printed slots and slot coupled microstrip antennas
abstract: A method for the analysis of slot type discontinuities in microstriplines is presented. The method is based on the equivalent principle, reciprocity theorem, and a moment solution using the spectral Green's function for dielectric slabs and can be used to analyze a number of slot coupled microstrip antennas, such as slot coupled multilayer patch antennas or a finite array of slot coupled patch antennas. Two examples, the analyses of a slot coupled patch antenna and of a finite array of printed slots, are given.<ETX>

title: Near Field Radiation Exposure Control in Slot Loaded Microstrip Antenna: A Characteristic Mode Approach
abstract: Microstip antenna topology is commonly loaded with a narrow slot to manipulate the resonance frequency or impedance bandwidth. However, the tuning of the resonance frequency or impedance bandwidth results in the variation of the current and field distributions. In this regard, this work adopts the concept of characteristic modes to gain an initial understanding of the perturbation mechanism of the rectangular patch when loaded with a slot. The performance of microstrip antennas with finite ground plane is then studied using full wave simulation. It has been found that the distribution of the induced current density is highly dependent on the orientation of the slot The incorporation of a narrow slot suppresses the nearby orthogonal eigen mode and, as a consequence, the radiation behavior is affected. Specifically, in the presence of biological tissues in the near field region, both antenna input impedance properties and the realized gain are dependent on the slot orientation. Different examples are included for understanding the impact of slot loading on the energy absorption by biological tissues, by calculating the the specific absorption rate (SAR) The proposed analysis facilitates the design of miniaturized antenna geometries for biomedical applications via systematic loading of narrow slots.

title: Dual polarized slot cut elliptical shaped microstrip antennas
abstract: This paper proposes a novel Multi band dual polarized elliptical shaped microstrip antenna cut with square and rectangular slot. The square slot in elliptical patch degenerates patch TM11 and TM21 modes into two orthogonal modes to realize multi band characteristics. The optimization of the input impedance at degenerated resonant modes is done by the introduction of the rectangular slot to realize optimum bandwidth of 1 to 2% in 1000 MHz frequency range. The proposed dual polarized configuration yields broadside radiation pattern characteristics over all the resonant mode frequencies.

title: Rectangular slot cut circular microstrip antennas
abstract: Multi band dual polarized circular microstrip antenna cut with circular and rectangular slot is proposed. The circular slot in circular patch degenerates patch TM11 and TM21 modes into two orthogonal modes to realize multi band characteristics. The rectangular slot helps in optimizing the input impedance at degenerated resonant modes to realize optimum bandwidth of 1 to 2% in 1000 MHz frequency range. The proposed dual polarized configuration shows radiation in the broadside direction for all the resonant mode frequencies.

title: OPTIMALIZATION OF MICROSTRIP SLOT ARRAY ANTENNAS FOR MULTI WIDEBAND
abstract: Microstrip slot antenna fed by matching network of microstrip line to increase very wide bandwidth and multiband is proposed. The microstrip line composed of multi tuning stubs is used to control slots antenna real impedance to match with impwdance cahracteristic of feeding line so that it could increase the bandwidth. The design are achieves good input impedance in the ranges frequency of 1.3 5.1 GHz for single slot and 1.1 6.4 GHz for two slots. The bandwidths of antennas become very wide if the slots made in array configuration. The measured return loss S11 agrees well with the simulation results for single slot as axample.  microstrip slot antenna, array configuration, network impedance, multi tuning stub.

title: Design Implementation and Experimental Comparison between Two Dual Polarized 2 4 GHz Microstrip Patch Antennas
abstract: This paper presents the design and implementation of two dual polarized microstrip patch antennas for 2.4GHz Inband Full Duplex (IBFD) wireless applications. Both antennas use orthogonal feeding ports but differ in feeding structures. The performance of both implemented antennas has been compared by measuring the interport isolation (S12) at required operating frequency around 2.4GHz. The implemented quarter wave microstrip fed antenna provides 43dB interport isolation while slot coupled version has 70dB isolation between transmit and receive ports at centre frequency. The slot coupled antenna provides more than 55dB interport isolation for 50MHz antenna`s 10 dB input impedance bandwidth.