The number of complaints will go up with the setting up
filter centers and a mechanism will be evolved to deal with them in a befitting manner.
In October 1943, the GOC and the
filter centers were taken off 24-hour basis and put into reserve, being activated after that only occasionally for tests and training, and completely deactivated on the continent in 1944 (I believe they continued on the Hawaiian islands until V-J Day).
Using portable VHF radios and field telephones, these soldiers would "voice-tell" their observations of aircraft sightings back to the
filter center Their reports were incorporated into the picture to fill out any gaps in radar coverage.
A = peak in-band amplitude (V) f = frequency |f.sub.c~ = the IF
filter center frequency (zero for a lowpass filter) BW = 3 dB filter bandwidth X = a constant = 1 for a lowpass filter = 2 for a bandpass filter n = the number of reactances for a lowpass filter = the number of resonators for a bandpass filter
To verify the design principle, the
filter centered at 3.5 GHz is fabricated on a substrate with dielectric constant [[epsilon].sub.r] = 2.65 and thickness h = 1 mm.
The second example is an in-line fifth-order
filter centered at [f.sub.0] = 5.1 GHz with bandwidth equal to 300MHz.
For perylene, 5 nm band pass filters centered at 464 nm and 473 nm were used; for BOS, 10 run bandpass filters centered at 420 nm and 436 rim were used; and for BPP, a 10 nm bandpass
filter centered at 400 rim and a 40 rim bandpass
filter centered at 500 nm were used.
The transfer standard is an erbium-doped fiber amplifier that is coupled to a linear polarizer and a narrow-band optical
filter centered in the 1550 nm wavelength range.
* A notch
filter centered at 825 Hz is used instead of 1020 Hz.
A narrow-band
filter centered on 12Hz and with a bandwidth of 1Hz is used to reject drag noise and the shortest span clearly distinguishable with this configuration is 2 meters.
To verify the design principle, the
filter centered at 1.9 and 2.6 GHz are fabricated on a substrate with dielectric constant [[epsilon].sub.r] = 2.65 and thickness h = 1 mm.