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Transitions between microstrip and NRD-guide are required by integrating NRD circuits to planar circuits and NRD circuit measurement. The transition proposed in [1] offers a promising solution in view of practical applications, but it has to be accurately modeled and optimized to achieve its best possible performance. In this paper, the transmission line matrix (TLM) method has been successfully used...
A circular cylindrical metallic cavity loaded with homogeneous lossy dielectric slab is analysed. The mode tuning effects of loaded cavity are investigated, wherein the effect of the losses is introduced through the complex values of the dielectric constant and the frequency. The characteristic equation is obtained using the transverse resonance method. The complex resonant frequencies are determined...
This paper present a numerical investigation of discontinuities between coplanar waveguide (CPW) and slow-wave MIS CPW with inhomogeneous doping regions. The frequency-domain TLM (FDTLM) method is applied to calculate the scattering parameters for the abrupt transition from a normal CPW on insulating substrate to an MIS CPW on doped substrate. The effect of various lateral widths of the doping region...
To analyze high Q circuits, we need a very accurate method. Traditional methods, such as 2D planar circuit, Modal or Okoshi's, 3-D methods, moment or variational methods, are not versatile or accurate enough for these circuits. In this paper, a better method, the combined 2D plus variational method together with reciprocity and zero tangential field, will be presented to analyze microstrip patches.
In this paper, physical model for microwave pulse coupling into cavities through narrow slots is presented, and the equation for predicting the dependence of coupling on the polarization directions of the incident pulse is derived. The modified FDTD method is used to simulate the coupling process. We observe the resonant and enhancement effects which occur in the process, and present the condition...
This paper describes an efficient method for the analysis of cylindrical cavity resonator structures with inhomogeneous dielectric medium. In this approach, the field equations are formulated using the Laplace-domain finite element method and are solved using the complex frequency hoppoing (CFH) technique. CFH is a moment matching technique which has been used successfully in the circuit simulation...
The use of synthetic aperture radar on aircraft became well established in the first half of the seventies. It has enabled much better resolution to be obtained than that achievable with conventional radar. A conventional side looking imaging radar achieves range resolution by employing short RF pulses and azimuth resolution by means of a narrow antenna beamwidth. To create a narrow beamwidth with...
The Canadian Radarsat satellite was launched on November 4, 1995 and is now in routine operation. Radarsat's payload consists of a Synthetic Aperture Radar (SAR) imaging instrstrument, and it is the first operational satellite SAR with an antenna which can reconfigure its elevation beam electronically. The SAR Antenna is a large deployable slotted waveguide planar array (1.5m by 15m) operating at...
At L-band the most practical implementation of space borne SAR antennas requires the use of microstrip radiating elements. However, printed antennas are usually characterized by inherently narrow bandwidth which limits the range resolution capability of the system. In order to develop an L-band SAR antenna design with enhanced bandwidth performance Spar and CAL have performed studies aimed at 5% (1...
The next generation of civilian, satellite based synthetic aperture radar is expected to be multispectral with polarization synthesis, cross polarization and multi-mode capabilities. In order to minimize the overall size of the antenna subsystems required by these radars, techniques are being investigated which will allow the aperture to be shared between the multiple frequency bands and multiple...
The first Canadian remote sensing satellite was launched in November 1995. The payload is a Synthetic Aperture Radar (SAR). The SAR antenna is a 15m.∗1.5m. C-band horizontally polarised (HP) phase-scanned planar array. The scanned antenna beam can illuminate a portion of the earth's surface which is selected independently of the position of the satellite in its orbit. The beam reconfigurability property...
For the Synthetic Aperture Radar (SAR) applications antenna candidates with dual-polarized dual-band capability are investigated. The microstrip technology is considered and several antenna configurations are selected, analyzed, designed and evaluated. Here, three different candidates are presented that use different combinations of substrates and antenna geometries. Their performance is briefly reviewed...
A proposed baseline space-borne Advanced SAR active array concept is a dual-frequency (L and C bands), dual polarization, planar array, with 1920 C-Band T/R modules and 240 L-Band T/R modules, distributed behind the radiating aperture. It comprises five panels, each one approximately 4m in elevation by 3.2m in azimuth, for a total antenna aperture size of 4m × 16.0m. Each panel is subdivided into...
Channel variations due to movement of people in the indoor propagation environment are expected to be particularly significant in the SHF/EHF bands. This paper reports CW measurements performed at 30.1 GHz between two fixed terminals in a single room to determine the amplitude and speed of temporal variations of the envelope when individuals are moving in the environment. In particular, it is shown...
In intelligent vehicle and highway systems, intelligent vehicles must have communication equipment and radar sensors. The communication equipment is used to communicate with other vehicles or road-side base stations, and the radar sensors detect preceding vehicles on the road. Therefore, to be widely used in the future, this equipment must be economical. For economical equipment to become a reality...
Radio channel models developed for traditional macro-cellular systems can not be used for micro- and pico-cellular environments of modern wireless personal communication systems (PCS). This is mainly because of distinct differences in propagation characteristics and much smaller outdoor and indoor micro-cell sizes [1]. It is therefore essential to develop site specific models [2], [3] for a realistic...
In this paper a procedure for the synthesis of the receiving MMDS corner reflector antenna is given. The antenna was modeled and its performances have been analysed as functions of the antenna parameters. Optimisation criteria were based on the specific area of the comer reflector antenna implementation. It has been shown that synthesised antenna satisfies given requirements. Optimal antenna was designed...
This paper presents a technique for determining the scattering coefficients of the Generalized Scattering Matrix (GSM) for an infinite planar structure whose operation is prescribed. The technique is partly a synthesis tool in that it allows to identify some geometrical properties of the structure from the relationships between various coefficients of the GSM. These relationships are cast into a formalism...
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