Design of Frequency Tunable Compact Antenna and Millimeter to Terahertz Array Antennas

As increased bandwidth demands continue to rise and overly crowded existing bands need be relieved, the study of frequency tunable and higher frequency array antennas is needed. By tuning the resonant frequency of an antenna, the bandwidth increases since the operating frequency has increased from the tuning. Also, higher frequency antenna designs are beginning to take flight to alleviate the lower bands and allow for an increase in bandwidth. Both the methods can bring a solution to the increased bandwidth demand.;Thesis work begins with the design of a novel single feed planar antenna with 4G tunable bands and consistent upper LTE bands. This antenna is simulated using full wave analysis tool, fabricated and measured. This antenna shows near omni-directional radiation pattern exhibiting gain levels from -4.25dBi in the lower band to 2.69dBi in the upper band. The impedance matching for the lower band can be tuned from 690 MHz - 970 MHz while the higher band is consistently present between 1.29 GHz -- 2.05 GHz, both based on S 11 ≤ - 6dBi.;To begin the stepping stone for higher frequency planar array antenna designs, first an 8x8 array antenna is designed in the Ka band. The impedance matching for this design is measured 28.34 GHz -- 32.09 GHz having fractional bandwidth of 12.41% based on S11 ? - 10dB. This array antenna was fabricated and experimentally verified for its impedance matching and radiation performances.;Next, a 4x4 antenna array is designed for operation in the 5G wireless band and using 0.07mm quartz material. The design has matching band from 53.6 GHz -- 54.0 GHz having fractional bandwidth of 0.7435% based on S 11 ≤ -10dB.;Finally, a 2x2 array antenna having a center frequency of 300 GHz with fractional bandwidth of 11.2% based on S11 ≤ -10dB is designed. This 2x2 array antenna was also designed using 0.07mm thick quartz substrate material so as to fabricate using the photolithography method due to the limitations of the standard method of fabrication using a milling machine. This antenna could not be finalized and experimentally verified due to the unavailability of required lab resources for THz range.