10 GHz-Range Surface Acoustic Wave Low Loss Filter Measured at Low Temperature

Abstract

We have studied the time series of full disk integrated soft and hard X-ray emission from the solar corona during 2004 January to 2008 December, covering the entire descending phase of solar cycle 23 from a global point of view. We employ the daily X-ray index derived from 1 s cadence X-ray observations from the Si and CZT detectors of the "Solar X-ray Spectrometer" mission in seven different energy bands ranging between 6 and 56 keV. X-ray data in the energy bands 6-7, 7-10, 10-20, and 4-25 keV from the Si detector are considered, while 10-20, 20-30, and 30-56 keV high energy observations are taken from the CZT detector. The daily time series is subjected to power spectrum analysis after appropriate correction for noise. The Lomb-Scargle periodogram technique has shown prominent periods of ∼13.5 days, ∼27 days, and a near-Rieger period of ∼181 days and ∼1.24 yr in all energy bands. In addition to this, other periods like ∼31, ∼48, ∼57, ∼76, ∼96, ∼130, ∼227, and ∼303 days are also detected in different energy bands. We discuss our results in light of previous observations and existing numerical models.

High-frequency programmable acoustic wave device realized through ferroelectric domain engineering

“…Bearing in mind that for a typical relaxor, v s is in the range of 2.5-6 km/s, the operational frequency of such SAW devices has a theoretical upper limit of around 6 GHz (purely on the basis of the speed of sound and the spacing of the electrodes), whereas in practice, the SAW filters used in contemporary 3G and 4G cellphone telecommunication networks typically operate below 2.5 GHz. Whilst, in principle, SAW resonators operating at higher frequency (up to 10 GHz) have been demonstrated, 4 with electrodes as small as 90 nm fabricated by electron-beam lithography, the losses associated with the high resistance of such small electrodes rendered the devices somewhat impractical. The electrodes suffer from Joule heating and electromigration 5 and delaminate under high power, which is only overcome by either operating at low temperature (below 10 K) or by using exotic electrode materials.…”