Advanced Microwave Ferrite Research (AMFeR): Phase Four
Abstract
The purpose of this research endeavor is to devise ferrite materials for microwave, self-biased circulator applications. To this end, the research team focused on two key activities. The first was the development of a ferrite/epoxy composite that can be directly injected into a dielectric substrate. As the ferrite cured, two external magnets were placed on both sides of the ferrite to align the ferrite moments; once cured, the moments were locked in place to form a self-bias structure. Microstrip traces were patterned on it to form a microstrip circuit. Frequency-swept S-parameters measurements were made to ascertain the device's response. On average, the device exhibited excellent return loss and isolation on the order of 20 dB or more over a narrow band of 1 GHz centered at 25GHz. However, the insertion losses were unacceptable at about 11.7 dB. This latter outcome is directly related to the large linewidths. In addition to fabricating our own ferrites, we also employed strontium-ferrites that were fabricated by Countis Laboratories. These ferrites exhibit stronger crystalline anisotropies than their barium-ferrite cousins, but are nevertheless suitable for this application. When used in a self-biased circulator, the response of the circulator was marginally acceptable.
Document Details
- Document Type
- Technical Report
- Publication Date
- Oct 15, 2009
- Accession Number
- ADA507758
Entities
People
- Jeffrey L. Young
Organizations
- University of Idaho