By Topic

High frequency fundamental resonators and filters fabricated by batch process using chemical etching

Sign In

Cookies must be enabled to login.After enabling cookies , please use refresh or reload or ctrl+f5 on the browser for the login options.

Formats Non-Member Member
$31 $13
Learn how you can qualify for the best price for this item!
Become an IEEE Member or Subscribe to
IEEE Xplore for exclusive pricing!
close button

puzzle piece

IEEE membership options for an individual and IEEE Xplore subscriptions for an organization offer the most affordable access to essential journal articles, conference papers, standards, eBooks, and eLearning courses.

Learn more about:

IEEE membership

IEEE Xplore subscriptions

4 Author(s)
Ishii, O. ; Toyo Commun. Equipment Co. Ltd., Kanagawa, Japan ; Morita, T. ; Saito, T. ; Nakazawa, Y.

The small sized 1st intermediate frequency (IF) filters at center frequency range of 70 MHz to 150 MHz and passband widths of ±5 to ±100 kHz with sharp selectivity are required in mobile communication systems such as mobile and portable cellular phone. Our solution to employ fundamental mode monolithic crystal filter (MCF) assembled in surface mountable package. We describe here in detail, the design approach including batch process etching technology. Through photolithography, 56 patterns are chemically etched on one wafer (25 mm×20 mm). Then, a similar etching process automatically adjusts the wafer thickness in accordance with frequency. For the MCF, the frequency of split electrodes and the degree of coupling between them are automatically adjusted by an accurately positioned mask evaporation process controlled by a computer. Further, we describe suppression of the spurious response, technology for realizing wide bandwidth and high stopband attenuation characteristics. By our above developed technology, we achieved 90 MHz miniaturized IF filter with 1/15 volume reduction of conventional 3rd overtone mode MCF, still possessing the same characteristic of conventional one. Also, we achieved 130 MHz of middle band with suppression of spurious response in wide stopband frequency range, and 71 MHz linear phase wide ±88 kHz band with the group delay distortion 0.9 μs over f0±80 kHz

Published in:

Frequency Control Symposium, 1995. 49th., Proceedings of the 1995 IEEE International

Date of Conference:

31 May-2 Jun 1995