A Novel Approach for Bandwidth Enhancement of Slot Antennas
Abstract
A novel approach is presented to improve the bandwidth of slot antennas. The technique is based on manipulating the field distribution along an ordinary resonant slot structure using the feed line and creating a dual resonance behavior. Hence without changing the length of the antenna its bandwidth is increased by more than 200% relative to a narrow slot. The field distribution along the slot at a frequency slightly above its natural resonance is manipulated by a narrow microstrip line feeding the slot near one of the two edges. By proper choice of the slot width, feed location, and microstrip feed line a fictitious second resonance can be created by establishing a null in the electric field distribution along the slot near the feed line. This null is resulted from the superposition of the microstrip near field and the slot field excited by the displacement current. A prototype is designed and tested at the center frequency 3.4 GHz. A large bandwidth of 37% is achieved without any constraints on impedance matching or complexity in the antenna structure. Also bandwidth enhancement of a miniaturized slot antenna using parasitic coupling is presented. The antenna occupies a small area of 0.15 lambda(sub 0) x 0.15 lambda(sub 0) and can have up to 3% bandwidth.
Document Details
- Document Type
- Technical Report
- Publication Date
- Sep 01, 2003
- Accession Number
- ADP017236
Entities
People
- Kamal Sarabandi
- Nader Behdad
Organizations
- University of Michigan