Multi band multi polarised fractal antenna for white space TV band

ABSTRACT

Designing a fractal antenna for white space TV band frequencies is the main goal of the suggested work. In this design 4 iteration Koch snowflakes patch is used to get multiband. As the number of iterations increased size of the antenna is going to reduce. Further 4^th iteration Koch snowflakes slots have been created in the patch. By introducing a fourth iteration cross slot into the ground plane, three bands have been created. Circular polarisation is attained through the incorporation of cross slots in the ground plane, inducing a phase shift between vertically and horizontally polarised electromagnetic waves. The antenna primarily operates within the last frequency bands (686–806 MHz) with linear polarisation. However, it can also function in the initial frequency band (487–540 MHz) with left-hand circular polarisation. The physical size if antenna is reduced by 38 mm with a gain of 4.5dBi. Axial ratio bandwidth (481–552 MHz) is 71 MHz. Axial ratio bandwidth is 18 MHz more as compared to impedance bandwidth. The same antenna can work in linear polarisation as well as circular polarisation. Multi-polarised, multiband antenna with impedance bandwidth of 10.3% (1^st band) and 16.08% (last band) is designed for white space TV band frequencies.

KEYWORDS:

• White Space TV band
• Koch snowflake fractal
• fractal slot
• cross slot
• defected grocund

Disclosure statement

No potential conflict of interest was reported by the author(s).