3 GHz Frequency and Signal Level Meter
Built around a CPLD and a dsPIC microcontroller
This handy instrument measures frequencies from 50 MHz to 3 GHz with an accuracy of 10 ppm and provides an indication of the signal level over a range of –40 dBm to +10 dBm. Readings are displayed on a three-line LCD module, and the instrument is powered by three standard AA cells.
Materials
Gerber file
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Extra info / Update
Features
* Frequency measuring range: 10 MHz to 3 GHz
* Frequency measurement error less than 10 ppm (0.001%)
* Signal level measuring range: –40 dBm to +10 dBm (0.1 ?W to 10 mW into 50 Ohm) over the range of 300 MHz to 2.8 GHz
* 146 readings per minute
* Power source: three 1.5 V AA cells or a 5 V AC mains adapter (min. 180 mA)
* Maximum current consumption at 5 V input: 170 mA
* Battery life with three 2000 mAh NiMH cells: 18 hours continuous operation without LCD backlighting or 11 hours with backlighting
Component list
R101 = 56Ohm
R104 = 4.99kOhm
R105,R229,R231 = 0Ohm
R200 = 10kOhm
R201,R303,R308 = 47kOhm
R202,R211,R226 = 33kOhm
R203,R210,R301,R302 = 100kOhm
R220,R221,R222 = 15kOhm
R225 = 150kOhm
R230,R235 = 1kOhm
R232,R293 = not fitted
R236 = 18kOhm
R250,R25 = 39Ohm
R290,R291,R292 = 4.7kOhm
R304,R305,R306,R307,R404 = not fitted
R401,R402,R403,R405 = 18Ohm
R406 = 82Ohm
Capacitors
C101,C226,C230,C231,C232,C301,C302,C303 = 100nF
C102,C110,C403,C415 = 100pF
C104,C105,C233,C401,C402,C404,C413,C416,C418,C419,C422,C423,C425 = 1nF
C106,C109 = not fitted
C107,C108 = 1pF
C200,C201,C210 = 2?F
C202,C211,C251,C252 = 1?F
C240,C241 = 18pF
C250 = 470nF
Inductors
(SMD0603)
L101 = 1.5nH
L401 = 4.2?H
Semiconductors
D200,D201,D202,D205,D225,D226,D227,D228 = NSR1020 (SOD323-W)
D204,D235 = 3.3V zener diode (SOD123)
D206 = 5.6V zener diode (SOD123)
IC101 = LT5538
IC200,IC210 = MCP1824 (SOT23-5L)
IC230 = DSPIC33FJ32GP204-I/PT (TQFP44), programmed
IC301 = EPM240T100C3N (TQFP100), CPLD (Altera)
IC401 = LMX2485E (LLP24), PLL (National Semiconductor)
IC402 = ABA-31563 (SOT363), wideband amplifier (Avago)
Q250 = BSS123 or SN7002W (SOT23)
VR230 = TL431 (SOT23-5), voltage reference (TI)
Miscellaneous
IC250 = EA DOGM163W-A, 3.3V-LC-Display, 3x16 characters (Electronic Assembly)
JP001 = DC adaptor socket, PCB mount
JP100 = SMA socket, 142-0711-881 (Emerson/Johnson)
JP200 = (optional) 2-pin pinheader (battery connection)
JP230 = 2-pin pinheader with jumper (if required)
JP235 = 5-pin pinheader, right angled
JP301 = 6-pin pinheader, right angled
JP302 = 6-pin pinheader, 2-row (if required)
R205 = self heasling fuse 30V/0.2A (SMD1210), Littlefuse 1210L020WR (e.g. Farnell 1596997)
S200,S220,S221,S222 = pushbutton, 1 make contact, PCB mount
X240 = 18MHz quartz crystal (HC49/SMD)
X301 = CFPT-126 (LF TVXO009920) from IQD, temperature compensated 40MHz SMD quartz oscillator (Farnell #1100757)
Enclosure: Bopla Type BS404 F-7035
PCB # 100760-1
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