MEL’S DOG & PONY SHOW RADIO FREQUENCY FILTERS A radio frequency filter is an electronic circuit...
-
Upload
august-howard -
Category
Documents
-
view
219 -
download
0
Transcript of MEL’S DOG & PONY SHOW RADIO FREQUENCY FILTERS A radio frequency filter is an electronic circuit...
MEL’S
DOG & PONY SHOW
RADIO FREQUENCY FILTERS
A radio frequency filter
is an electronic circuit that
will allow or not allow a
band of frequencies to
pass thru it
RADIO FREQUENCY FILTERS
There are 2 basic
types of filters
SERIESOR
PARALLEL
RADIO FREQUENCY FILTERS
Today we will be discussing
SERIES FILTERS
More commonly called
The Series Resonant Circuit
RADIO FREQUENCY FILTERS
The purpose of a
SERIES RESONANT CIRCUIT
is to allow a specific band of
frequencies to pass thru it
RADIO FREQUENCY FILTERS
The simplest
SERIES RESONANT CIRCUIT
looks like this
RADIO FREQUENCY FILTERS
RADIO FREQUENCY FILTERS
Now, to design our Series Resonant Circuit we will need to do some math
These are the formulas we will need
RADIO FREQUENCY FILTERS
PRIMARY ASSUMPTION
The antenna is a standard Half-Wave Dipole
The antenna is tuned to the center of a band
RADIO FREQUENCY FILTERS
RESONANCE AND REACTANCE FORMULAS
2 * pi * L Cf =
1
4 * pi * f2 2LC =1
4 * pi * f * L22C =1
XL = 2 * pi * f * L2 * pi * f * C
1XC =
F
BWQ =
4 * pi * f * CL =
12 2
Inductance
in Henries
Capacitance
in Farads
RADIO FREQUENCY FILTERS
VSWR EQUATIONS
P = 1 2Z Z
Z1 Z2
VSWR = 1 P
1 P
RADIO FREQUENCY FILTERS
COIL WINDING FORMULASL = self inductance in microhenrys
N = total number of turns
r = mean radius of the coil in inches
l = length of coil in inches
9r + 10lL =
(r N) 2
L(9r +100l)
rN =
l
r
TIME FOR THE
SPREAD SHEET
RADIO FREQUENCY FILTERS