A passive UHF RF identification (RFID) tag IC with embedded 2-KB ferroelectric RAM (FeRAM) for rewritable applications enables a 2.9 times faster read-and-write transaction time over EEPROM-based tag ICs. The resulting FeRAM-based tag has a nominally identical communication range for both read and write operations, which is indispensable for data write applications. The evaluated tag communication range with a folded dipole antenna is from 0 m to 4.3 m, at the 953-MHz carrier frequency with 4-W transmitting Effective Isotropic Radiated Power (EIRP) from a reader/writer. The developed tag IC features two circuit blocks to maximize the communication range in 0.35-m CMOS/FeRAM technology.First is a CMOS-only full-wave rectifier, which can improve the measured efficiency by up to 36.6% by reducing the input parasitic capacitances and optimization of multiplier structure. This efficiency is more than twice that of previously-published results. Second is a low-voltage current-mode ASK demodulator to accommodate a low-breakdown voltage of FeRAM, which converts the ASK power modulation into a linearly modulated current over an incoming power range of 27 dB, corresponding to the entire communication range. The developed demodulator can thus resolve the primary design tradeoff issue between device protection and detection sensitivity in the conventional voltage-mode demodulator.Index Terms-CMOS-only full-wave rectifier, current-mode demodulator, electromagnetic radiative interference, ferroelectric random access memories, identical read/write communication, UHF radio frequency identification.

The wave propagation properties of short internal gravity waves (wave length *<10km) are very different from those of long ones (*100km) owing to nonhydrostatic effects. Considering this observation, we parameterize the orographic gravity wave drag (GWD) in two ways. The major difference between two schemes is in the vertical partitioning of drag forcing, i, e., one weighs mainly in the stratosphere (type A) and the other in the troposphere (type B). We apply them to a global numerical weather prediction model and study their impacts on medium-range forecasts.These two schemes individually reduce systematic forecast errors and their combination achieves the best forecast skill. In the troposphere, the impacts of these two schemes, including time evolutions, are very similar to each other. Hence, the troposphere is considered to be insensitive to the vertical partitioning of GWD at least within a medium-range time scale. In the case of the type A scheme, most of the drag forcing given to the lower-stratospheric mean-flow is rapidly transferred downward and contributes to change in the tropospheric circulations. In the stratosphere, the impacts of the type A scheme is much larger than those of the type B, especially in a short-range time scale. The stratospheric impacts of the type B scheme gradually increase after a few days, possibly corresponding to a time scale required for the vertical propagation of Rossby waves excited in the lower troposphere.The improvement of forecasts is evident in the zonal-mean fields. Although the type A scheme almost eliminates the westerly errors in the stratosphere, there still remain westerly errors in the troposphere. The type B scheme effectively reduces the remaining tropospheric errors. This may justify a need of tropospheric drag forcing, like the type B scheme.

The effects of orographic gravity wave drag (GWD) on zonal-mean fields of medium-range forecasts are analyzed by means of the transformed Eulerian-mean (TEM) method. Results show that the geostrophic adjustment to GWD behaves very differently between the stratosphere and troposphere.In the troposphere, both the tropospheric and stratospheric GWDs significantly change EliassenPalm (EP) flux divergence due to large-scale (model-resolvable) waves. The change in the EP flux divergence is much larger than the net change of tonal wind and GWDs themselves and it is almost balanced with the change in the Coriolis acceleration term due to meridional flows. Among wave activities, transient gravity waves resolved in the model are considered to play important roles in the vertical redistribution of additional wave moments due to GWD.In the stratosphere, the stratospheric GWD induces a hemispheric single cell meridional circulation. The vertical motions in this cell cause significant temperature changes. The Coriolis acceleration due to GWD-induced meridional flows is almost balanced with the GWD itself. In contrast with the troposphere, EP flux divergence is less affected by GWD.From the view of Lagrangian-mean meridional circulation, diabatic heating in the tropics and wave, mean-flow interaction due to planetary-scale waves have been recognized mainly to drive a hemispheric single cell circulation (the so-called Brewer-Dobson circulation) in the lower-stratosphere. Our results indicate that the stratospheric GWD contributes to the maintenance of the single cell circulation as well. Especially in the midlatitudes of the northern hemisphere, the GWD can be regarded as an important forcing and considerably enhances lower-stratospheric downward motions in the polar side of the subtropical jet stream. It might affect significantly the transport of trace constituents in the stratosphere.