Kamil Pitra

Wideband feeders for millimeter-wave horn antennas

In the paper, the design of millimeter-wave horn antennas is described. Attention is turned to the proper construction of a wideband feeder of the horn. For the final antenna structure, a bow-tie dipole and a Vivaldi antenna were chosen. The antenna construction is aimed to provide a wide bandwidth on one hand and a high gain on the other hand. An experimental comparison of horn antennas fed by a bow-tie dipole and a Vivaldi slot is the original contribution of the paper. Antennas are compared considering computer simulations in CST Microwave Studio and measured data.

Wideband antenna for DVB-T

The paper deals with a unit of broadband transmitting antenna used for digital TV broadcasting. The unit of antenna consists of four vertically oriented dipoles. The improvement of antennas parameter is achieved by replacing cylindrical dipoles by bowtie type. The feeding network of antennas unit is discussed here. Finally, unit of simulated antenna in CST Microwave Studio is demonstrated and obtained results are presented.

Design of circularly polarized terahertz antenna with superstrate (cover) layer

We present the design of a circularly polarized antenna operating at 996 GHz. The antenna meets the requirements demanded by security applications where the orientation of the hidden object might not be optimal from the detection viewpoint. In order to radiate high power, we integrated an LT GaAs photomixer into the antenna structure considering a matrix realization with an interdigital electrode, choke filters and a superstrate layer. Since a good impedance matching between the antenna and the photomixer is essential for radiating the high output power, we developed an equivalent model of the interdigital electrode (IDE) and computed its capacitance in order to precisely design the matching. The addition of a superstrate layer with a specific size will induce a significant effect on antenna performances. Particularly, the realized gain of the proposed antenna structure can be significantly increased.

Dual slot-superstrate terahertz antenna without Si-lens

Design study is presented concerning the structure of dual slot - superstrate antennas operating at 1 THz for signal sources LT-GaAs photomixer. The antenna directivity is strong enough to remove Si lens from the conventional THz emitter. The input impedance of the antenna was matched to the impedance of the photomixer to achieve high output power. The designed structure was verified by simulations in CST Microwave Studio.

Vertically polarized antenna system for television broadcasting services

In the paper, the design and simulation of a transmit antenna system with vertical polarization is discussed. The antenna is designed for television broadcasting services. The improvement of antenna properties is achieved by using a special balun with a shunt matching and an inner compensation transmission line. The feeding network of the antenna is deeply discussed. The antenna is simulated in CST Microwave Studio. Experimental verification of antenna properties is under preparation.