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We present the analysis of a quasi circular planar antenna for UWB applications. Analysis includes comparison of coplanar and microstrip feeding. Evolution from the circular antenna requires modifications in the structure and ground plane to soften the edges obtaining improvements in the antenna parameters agreeing with the theory proposed by John Kraus.… (More)
This paper shows the comparison of some of the most important satellite antenna feeders for fixed applications. The design procedure of the feeders is carried out in order to contrast their main electrical features with their manufacturing tolerance. The considered characteristics are: antenna gain, beamwidth, cross-polarization discrimination, side and… (More)
A highly omnidirectional UWB antenna is presented. The device is suitable for monitoring purposes. The measured bandwidth goes from 0.27 GHz to 17.7 GHz, with S<sub>11</sub> of ≤ -10 dB. The H-Field radiation pattern has an out-of-roundness less than ±3 dB in the entire band. The antenna has a structure of a π/4 bi-orthogonal… (More)
In this paper, the performance of a smart antenna system based on a linear array is evaluated. The results presented here include the antenna pattern. This procedure can reduce the interference level in a cellular communications system.
The scaling factor in a ultra-wideband antenna is investigated. Here is showed that the lower frequency limit of the bandwidth is reduced as the scaling factor is bigger than unity. Using the obtained results a UWB planar monopole antenna was designed. The measured antenna bandwidth goes from 650 MHz to 20 GHz for a VSWR ≤ 2. The radiation pattern remains… (More)
A novel active load linearizer is introduced to enhance the non-linear performance of a HBT Low Noise Amplifier. This active load is configured as a Current Source. The results of this structure are compared to an equally biased non-active loaded device, obtaining a higher third order Input Intercept Point (IIP3) around 17 dBm, and a higher compression… (More)
In this paper, a planarized directive UWB antenna is designed based on a revolution-surface body. The antenna performs from 5.2 GHz to 10.8 GHz with a highly stable directive radiation pattern, an average front to back lobe ratio of 20 dB and an absolute gain of 9.5 dB, all over the bandwidth.
A cylindrical hat-loaded method is employed to make monopoles behave as dual band resonators. The two frequency bands are obtained by perturbing higher propagation modes by modifying the hat length. The longer the cylindrical hat is, the lower the resonant frequencies are obtained. The hat length behaves as an inductive load, also increasing the electric… (More)