Thesis
Microstrip antennas with ring hybrid feeding structures for in-band full-duplex applications
Washington State University
Master of Science (MS), Washington State University
2017
Handle:
https://hdl.handle.net/2376/103701
Abstract
The information age has led to crowding of the consumer wireless network as more devices are using the same, limited frequency band. Currently these devices must operate at two frequencies, one to transmit, and one to receive, due to their compact nature. Were they to do both at the same frequency, there would be a high level of self-interference, in which the receive signal of a device would carry much of the transmit signal of that very same device because of the nearness of the signal. If this issue could be resolved such that each device could both transmit and receive at one frequency at any time, the capacity of these crowded wireless networks could be theoretically doubled. Such operation is known as in-band full-duplex. Presented here are three microstrip antenna system designs for use in in-band full-duplex applications. The radiating elements of the design are two monopoles, a probe-fed patch, and an aperture-fed patch, respectively. All three designs utilize a 180° ring hybrid element to reduce self-interference between a transmit and receive port. They are designed to operate in the 2.4 GHz WLAN band. The monopole design has a bandwidth of 100 MHz (4.2%), the probe-fed patch design 60 MHz (2.5%) and the aperture-fed patch design 40 MHz (1.7%). Measured in a reflective environment, throughout the operational band the monopole design has measured isolation below -35 dB, the probe-fed patch design -30 dB, and the aperture-fed patch design -45 dB. However, the peak measured isolation is instead -45 dB for the monopole design, -50 dB for the probe-fed patch design, and -60 dB for the aperture-fed patch design. All three designs offer reasonable gain and good radiation patterns that act omnidirectional or semi-omnidirectional. They are more compact than other antenna system designs meant to reduce self-interference that accomplish similar levels of reduction. These other attempts will be discussed in brief. Due to high levels of isolation and good efficiency, the designs also offer envelope correlation coefficients well below the accepted 0.3 threshold for multiple-input multiple-output designs, used here to quantify our simultaneous transmit and receive design.
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Details
- Title
- Microstrip antennas with ring hybrid feeding structures for in-band full-duplex applications
- Creators
- Gregory George Makar
- Contributors
- Tutku Karaçolak (Degree Supervisor)
- Awarding Institution
- Washington State University
- Academic Unit
- Electrical Engineering and Computer Science, School of
- Theses and Dissertations
- Master of Science (MS), Washington State University
- Publisher
- Washington State University; [Pullman, Washington] :
- Identifiers
- 99900525154301842
- Language
- English
- Resource Type
- Thesis