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This paper presents the design and implementation of dual band dual polarized multi-beam base station antennas. By utilizing the interleaved single band elements with asymmetrical non-uniform spacing arrangements, the proposed multi-beam antennas have the following dual band hybrid functions: normal L multiple beams at low band (0.698–0.96 GHz) and double 2L multiple beams at high band (1.71–2.36/1...
This paper introduces a new method of two-dimensional discrete complex images to evaluate the Sommerfeld's integral arising in the problem of a vertical magnetic dipole (VMD) over a Microstrip structure. Contrary to the conventional complex images method, which one has to find a new set of images for each new frequency, it is shown that the 2D images take into account the frequency dependence of Sommerfeld's...
This paper presents the design and implementation of dual band dual polarized hybrid base station antennas. By utilizing the integrated dual band elements, the proposed antennas have dual band hybrid functions: conventional 65degree beam at low band (698–894, or 790–960MHz) and bisector 33degree beams at high band (1.71–2.4GHz). After applying some mutual coupling and phase compensation techniques,...
For the first time, ferrite low temperature co-fired ceramic (LTCC) tunable antennas are presented. These antennas are frequency tuned by a variable magnetostatic field produced in a winding that is completely embedded inside the ferrite LTCC substrate. Embedded windings have reduced the typically required magnetic bias field for antenna tuning by over 95%. The fact that large electromagnets are not...
In this paper, the effects of t vector for GPOF approximation of a Green's function for a single layered microstrip structure have been evaluated. In order to do this, effects of T0 and dt variations and also the simple polynomial profile of non-uniform sampling strategy have been evaluated. The best value for each computation can be determined separately using different compromising policies between...
To obtain the best achievement when facing an antenna optimization problem, the first step is to choose a suitable model. Although, usually the design parameters in an antenna problem are some specific parameters such as Gain, VSWR, SLL or Bandwidth, in some cases it is needed to optimize a set of parameters simultaneously such as a beam shaping problem. These kinds of problems, which are mostly found...
In LEO satellite communications, each earth station observes the satellite only in short periods of time, in different directions with different slant ranges [1]. The purpose of this design is to create a link with fixed received signal level in different times and consequently independency of bit rate from the elevation angle. To compensate higher path losses for low elevation angles antenna's directivity...
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