Investigations on a multiband microstrip‐fed inverted‐F antenna with ground slots

Abstract

respectively, for the sample frequencies 7 GHz and 8 GHz where the main lobes are along -y direction in Figure 1 for both patterns. According to the results in these figures, the patterns are said to be symmetric and almost Gaussian. Besides, the patterns are quite insensitive to frequency changes in the given operation frequency band especially for H-plane that the patterns do not show crucial changes even for 1 GHz change in the frequency. The gains of the sole dielectric antenna are 13.1 dBi and 14 dBi for 7 GHz and 8 GHz, respectively where the gain of the antenna varies from 12.7 to 14.3 dBi within the frequency band 6.7-8.25 GHz.The cross-polarization characteristics, which is an another important fact for an antenna, are also examined for the given antenna. For this purpose, the copolarization and cross-polarization patterns of the antenna corresponding to E-plane and Hplane are given in Figure 11 and 12, respectively, for the sample frequency 7.5 GHz. According to these patterns belonging to 7.5 GHz, whereas the cross-polarization level is about 27 dB below copolarization level within the elevation angle range 90 6 30 (60-120) for E-plane, this level is about 30 dB below for the azimuth angle range 270 6 90 and about 40 dB below for the azimuth angle range 270 6 30 for H-plane. Throughout the frequency band 6.7-8.25 GHz, the relative cross-polarization level is at most À25 dB for elevation range 90 6 30 and À35 dB for azimuth range 270 6 30 . Therefore, a low cross-polarization system can be achieved by designing a proper parabolic reflector antenna, which takes the reflected fields of the proposed antenna within 30 beamwidth in both principal planes into account. CONCLUSION

Circularly polarized quad‐band monopole antenna of wireless communication system

“…So, multiband antenna design is very demanding and challenging task. That is why researchers are still working on design of multiband antennas with different promising structural configurations like slot type, PIFA, and monopole, antennas which may fulfill the requirements. In this context planar microstrip monopole antennas with various structures are very popular in multiband applications due to some inherent features such as light weight, low cost, easy fabrication, ease of integration within an environment of microwave circuit, and its radiation patterns characteristics.…”

A compact hepta‐band antenna for portable and embedded devices

“…In this situation, care must be taken to understand the interactions between neighboring elements at all of the resonances [2, 7]. Although additional frequency bands can be supported with extra resonant arms, the placement of slots in the ground plane can also be used to introduce resonances not previously supported by the existing structure [8, 9].…”