ULTRA PURE 125KHz SINE WAVE SIGNAL SOURCE (104)
(125ksine1)
For some RFID systems operating at 125KHz, a very
low distortion signal source reference is needed.
The circuit shown on this page produces a 10-volt
peak-to-peak signal into a 50-ohm load, with a
distortion of only 0.01%.
24db / Octave Linkwitz Riley : The type of
filter (Butterworth, Linkwitz-Riley ect.) indicates
the shape and roll off of the filter. The more
common Butterworth has its cut off frequency at the
-3db point. This point is .7071 the amplitude of the
pass band. The Linkwitz-Riley has its cut off
frequency at the -6db point.
Bandpass Filter (Single OpAmp) : A band pass
filter passes a range of frequencies while rejecting
frequencies outside the upper and lower limits of
the passband. The range of frequencies to be passed
is called the passband and extends from a point
below the center frequency to a point above the
center frequency where the output voltage falls
about 70% of the output voltage at the center
frequency.
DPPs program key parameters of bandpass filter:
12/12/2002 EDN - Design Ideas / The three-amplifier
implementation of the state-variable filter in
Figure 1 provides for second-order bandpass,
highpass, and lowpass responses. The strength of the
circuit, however, is in the bandpass response (VOUT/VIN),
in which it's easy to achieve high gain (G) and high
Q. These two characteristics are important in
applications in which selectivity is a key parameter
in the filter..
HighQ Bandpass Filter Is Well Suited To CurrentMode
Signal Processing : 03/04/02 Electronic Design -
Ideas for Design / Analog signal processing has
conventionally been viewed as a voltage-dominated
form of design. But voltage-mode processing can
restrict the system's dynamic range. There is also a
limitation on the input range of signals for linear
operation. An...