... synthesizer shown in Fig. P6. 7 provides 401 output frequencies
equally spaced by 10 kHz. The output frequencies are from 144 to 148 MHz.
FIGURE P6. 4
FIGURE P6. 5
FIGURE P6. 6
PROBLEMS 193
The reference ... in Fig. P6. 4.
6.5 Determine the output frequencies of the frequency synthesizer shown in Fig.
P6. 5 for N
1
¼ 10 and N
1
¼ 20. Note that f
R
¼ 1 GHz and N
2
¼ 100.
FIGURE P6. 2
FI...
... data. The second method is the cavity model [11]. This
model assumes the rectangular patch to be essentially a closed resonant cavity with
magnetic walls. The cavity model can predict all properties ... slot
Since antennas interface circuits to free space, they share both circuit and radiation
qualities. From a circuit point of view, an antenna is merely a one-port device with
an associated ....
... looking at the device terminals (driving point) [1]. The impedance
transformer network includes the device package and embedding circuit. The circuit
impedance seen by the device is
Z
c
ð f Þ¼R
c
ð ... resistance generates RF power from the
DC bias supplied to the active solid-state device. Figure 4.35 shows a general
oscillator circuit, where Z
D
is the solid-state device impedance and Z
C...
... the target moving toward the radar and the minus sign for the target
moving away from the radar. Let us consider the following two cases: The target is
stationary, and the target is moving.
7.7.1 ... beat
frequency at the receiving time (i.e., t
2
).
FIGURE 7.15 Block diagram of an FMCW radar.
7.7 FREQUENCY-MODULATED CONTINUOUS-WAVE RADAR 217
7.7.2 Moving-Target Case
If the target is moving,...
... of
stations provided a multiple-access technique is used. Frequency division multiple
access (FDMA) will distribute links established at the same time among different
frequencies. Time division multiple ... picture of this vision [8]. The
WLAN is for wireless indoor radio communication services or high-data-rate
communications. The system employs a central microcell hub (base station) that
se...
... various
services such as voice mail, email, video, messaging, data, and computer on-line
services. The direct link between satellites and personal communication systems can
provide voice, video, ... to cable television, and the end of the Cold War has made many military
technologies available to civilian applications. The global positioning systems
(GPSs), RF identi®cation (RFID) systems, ....
... line < 300 20±50 Moderate High Low Poor Fair
13
CHAPTER TWO
Review of Waves and
Transmission Lines
2.1 INTRODUCTION
At low RF, a wire or a line on a printed circuit board can be used to connect ... frequencies, the current tends to concentrate on the
surface of the wire due to the skin effect. The skin depth is a function of frequency
and conductivity given by
d
s
2
oms
1=2
2:1
whe...
... possible spurious frequen-
cies due to the two RF frequencies:
f
RF1
¼
nf
LO
À f
IF
m
ð5:29Þ
f
RF2
¼
nf
LO
þ f
IF
m
ð5:30Þ
The RF frequencies of f
RF1
and f
RF2
will generate spurious responses.
5.8 ... generated.
Any RF frequency that satisfies the following equation can generate spurious
responses in a mixer:
mf
RF
À nf
LO
¼Æf
IF
ð5:28Þ
where f
IF
is the desired IF frequency....
... of modulation is always needed in an RF system to translate a
baseband signal (e.g., audio, video, data) from its original frequency bandwidth to a
specified RF frequency spectrum. Some simple modulation ... time-sharing transmission is called time division
multiplexing.
3. The message is represented by a coded group of digital pulses. The effects of
random noise can be virtually eliminate...
... wireless
communications are frequency division multiple access (FDMA), time division
multiple access (TDMA), and code division multiple access (CDMA). Frequency
division multiple access and TDMA are ... frequency band, and interference caused by intermodulation and sideband
distortion.
10.3 TIME DIVISION MULTIPLE ACCESS AND TIME DIVISION
MULTIPLEXING
A TDMA or time division multiplexing (TDM)...