ISSN:
1089-7550
Source:
AIP Digital Archive
Topics:
Physics
Notes:
Surface acoustic wave directional couplers have long been known in both microwave and integrated acoustic applications. Such couplers are ideal for integration in acoustical signal processing devices, such as modulators or switches. There are, however, very few publications concerning the frequency response of these devices. This article represents both experimental and theoretical studies on the frequency response of directional couplers, with and without a thin strip deposited in the gap between the main channels. The beam propagation method, used in integrated optics, was adapted for acoustical directional couplers. It enabled the analysis and prediction of the frequency response of these types of couplers. Calculations were performed for the channels and interdigital transducers in the frequency range of 50–90 MHz. By using proper dimensions of the couplers' parameters, coupling efficiency for the higher part of the frequencies, in the receiver channel, was increased. This increase enables the selection of receiver frequencies and, therefore, a frequency channelizer could be developed. A thin strip between the main channels increases the coupling efficiency between the two channels and thereby reduces by about 30% the length of the coupler required for different frequency selections or conventional switches. This reduction makes it possible to obtain more compact devices with reduced losses. © 1996 American Institute of Physics.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1063/1.363784
