H. Matzner

Low cross-polarization, wideband antenna element based on a cavity slot

A wideband antenna having low cross-polarization level, based on a cavity slot element with a parasitic structure is proposed. The bandwidth of the antenna is 50% as demonstrated in the range 4.2 - 6.9 GHz (simulation) or 4.15 - 7.1 GHz (measurement). The cross-polarization level is -35 dB at the E-plane cut and -90 dB at the H-plane cut. The gain of the antenna is 6-7 dBi.

Sidelobe reduction in antenna arrays with different elements

Two methods for side lobe reduction in linear arrays are proposed. In the first method the side lobes are reduced by inserting different antenna elements (larger beamwidths in the center and narrower beamwidths in the edge), while all elements are equally illuminated. In the second method the distances between edge elements are larger than the distances in the center elements.

Investigation a class of shaped, radial microstrip dividers

Some compact and wideband 1:3, 1:4 and 1:5 shaped, radial microstrip dividers are proposed. The bandwidths of all the dividers are approximately 1 octave for SWR = 2, and the output ports have equal powers and phases. The special shapes of the dividers were designed by an extensive optimization process produced by the CST Microwave Studio software. Very good agreement between simulation and measurement was achieved.

A 1:8 waveguide feeding network for antenna arrays

A 1:8 feeding network for antenna arrays, based on rectangular waveguides is proposed. This divider is suitable for example for feeding box-horn arrays with distances 1.8 λ × 2–3 λ where grating lobe reduction is applied. Good agreement between simulation and measurement was achieved.

Multi beam antennas for cellular networks

Multi-Beam antenna arrays, made by H-plane waveguides with 4, 8 and 12 elements are proposed for cellular base stations. Simulated and experimental results show the beam directions, the gains, the side lobes and the overlapping between close elements, within the requirements for such products (very low loss, high power capability and flexibility in dimensions, in side lobes and in overlapping levels).

Designing and building of a circular GPS antenna

A circularly polarized microstrip antenna for global positioning system aims is proposed. This work presents the design of a dual-feed patch, which operates at single band (L1) of 1575 MHz. Circular polarization is achieved directly by the dual-feeding technique of a square patch through microstrip lines. The geometrical emplacement of the lines and the feeding point had been chosen in such a matter for the generated waves to be ninety degrees out of phase. The antenna is matched for 50 ohm input impedance, with 1.3% matching bandwidth and 0.63% right-hand circular polarization bandwidth. Good agreement between simulation and measurement was achieved.

Shared-aperture dual-band microstrip array

We present here two linear arrays mounted in the same aperture: the first array with 4 elements at 2.7 GHz (spacing 0.7λ) and the second array with 4 elements at 7.0 GHz (spacing 1.8λ). It is shown that by special design of the single high frequency element grating lobes are eliminated. The isolation between the two arrays is better than 14 dB.

Dual-polarized omni-directional antenna array based on cavity-slot elements

In this work, a cavity-slot, dual-polarized linear-cylindrical antenna array is proposed. The array is composed of 3 horizontal slots and 4 vertical slots at 3 GHz. The mutual coupling between a vertical slot and a horizontal slot is less than 30 dB, the average omni level ripple is 1 dB, and the average cross-polarization in the azimuth is less than 25 dB.

Ieee publishes a revision of the standard for definitions of terms for antennas: educational kit for antennas and radiation [education column]

The IEEE Standards Association published a revision of IEEE Std 145? in March 2014 [1]. This standard deals with def nitions, terminology, and parameters for antennas and for systems that use antennas as components. The last version of the standard was published 20 years ago, so this represents a major milestone for the worldwide antenna community.

A cheap matching component for correcting ill-matched antennas

A cheap matching component for correcting ill-matched antennas is proposed. The component is based on a parasitic longitudinal matching component. It is shown that this component can greatly correct input impedances which deviate from the designed value by -27j to +23j ohms.