ETC RF2412

RF2412
5
BROADBAND DUAL-CONVERSION
QUADRATURE MODULATOR
Typical Applications
• Digital and Spread-Spectrum Systems
• GMSK, QPSK, DQPSK, QAM
• Analog Communication Systems
• Portable Battery-Powered Equipment
• UHF Digital and Analog Transmitters
• Commercial and Consumer Systems
Product Description
1
.493
.486
Si Bi-CMOS
SiGe HBT
ü
.050
.413
.398
8 °MAX
0°MIN
.050
.016
Optimum Technology Matching® Applied
GaAs HBT
5
.018
.014
MODULATORS AND
UPCONVERTERS
The RF2412 is a monolithic integrated transmitter universal modulation IC capable of generating modulated AM,
PM, or compound carriers in the VHF/UHF frequency
range. The modulation is performed at VHF, then the
resulting spectrum is upconverted to a frequency range
between 100MHz to 1000MHz. The IC contains all of the
required components to implement the modulation function including differential amplifiers for the baseband
inputs, a LO 90° hybrid phase splitter, limiting LO amplifiers, two balanced mixers, a combining differential amplifier, a second upconvert balanced mixer, and an output
RF amplifier which will drive a 50Ω load. Since the modulation is performed at a low frequency, excellent amplitude balance and phase accuracy are obtained.
Si BJT
.009
.005
.299
.292
.092
.010
.008
Package Style: SOP-20
GaAs MESFET
Si CMOS
Features
• Single 3V to 6V Power Supply
VDD2 1
VDD1 2
POWER
CONTROL
PD 3
20 RF OUT
• Digitally-Controlled Power Down Mode
19 GND
• Dual Conversion
18 GND
• DC to 50MHz Modulation Frequency
I SIG 4
17 LO2
I REF 5
16 GND
Σ
Q REF 6
15 MIX IN+
Q SIG 7
14 MIX IN13 GND
GND 8
GND 9
LO1 10
-45°
+45°
12 MOD OUT11 MOD OUT+
Functional Block Diagram
Rev B1 010329
• 50MHz to 150MHz IF Frequency
• 100MHz to 1000MHz RF Frequency
Ordering Information
RF2412
RF2412 PCBA
Broadband Dual-Conversion Quadrature Modulator
Fully Assembled Evaluation Board
RF Micro Devices, Inc.
7625 Thorndike Road
Greensboro, NC 27409, USA
Tel (336) 664 1233
Fax (336) 664 0454
http://www.rfmd.com
5-7
RF2412
Absolute Maximum Ratings
Parameter
Supply Voltage
PD Voltage
Input LO and RF Levels
Ambient Operating Temperature
Storage Temperature
Parameter
Rating
Unit
-0.5 to 7.5
VDD +0.4
+6
-40 to +85
-40 to +150
VDC
VDC
dBm
°C
°C
Specification
Min.
Typ.
Max.
Caution! ESD sensitive device.
RF Micro Devices believes the furnished information is correct and accurate
at the time of this printing. However, RF Micro Devices reserves the right to
make changes to its products without notice. RF Micro Devices does not
assume responsibility for the use of the described product(s).
Unit
T = 25°C, VDD =5V, VREF =2.5V,
BB=100kHz, LO1=70MHz, LO2=700MHz,
VMOD =3.0VPP, SSB, unless indicated otherwise.
Modulation Signals (I&Q)
MODULATORS AND
UPCONVERTERS
5
Frequency Range
Signal Level
Reference Voltage (VREF)
Input Impedance to GND
Amplitude Balance
Quadrature Phase Error
Condition
DC to 50
2.2
2.0 to 3.0
3
0.1
1
MHz
VPP
V
kΩ
dB
°
50 to 150
30 to 225
-5 to +6
750-j400
MHz
MHz
dBm
Ω
100 to 1000
-5 to +6
600-j700
MHz
dBm
Ω
Without external 50Ω termination
+4
0
-4
dBm
dBm
dBm
VDD =5V, LO1,2 level=0dBm, SSB
Freq=200MHz to 500MHz
Freq=500MHz to 800MHz
Freq=800MHz to 1000MHz
+6
+3
-1
50
1.5:1
3:1
-155
dBm
dBm
dBm
Ω
dBm/Hz
Sideband Suppression
Carrier Suppression
35
25
dBc
dBc
First LO Harmonics
-20
-30
dBc
dBc
Unadjusted. Modulation DC offset may be
externally adjusted for maximum suppression. See Pin Descriptions.
Odd unfiltered IF
Even unfiltered IF
V
mA
Operating limits
VCC =5.0V
For 1dB compression
First LO Input
Frequency Range
Power Level
Input Impedance
For 30dB sideband suppression
For 20dB sideband suppression
Without external 50Ω termination
Second LO Input
Frequency Range
Power Level
Input Impedance
RF Output
Output Power
Output Power
Nominal Output Impedance
Output VSWR
Output Broadband Noise Power
VDD =6V, LO1,2 power=0dBm, SSB
Freq=200MHz to 500MHz
Freq=500MHz to 800MHz
Freq=800MHz to 1000MHz
Freq<600MHz
600MHz<Freq<1000MHz
Spurious
Single sideband modulation
Power Supply
Voltage
Current Consumption
5-8
3 to 6.5
31
35
Rev B1 010329
RF2412
Parameter
Specification
Min.
Typ.
Max.
Unit
Condition
Power Down
Turn On/Off Time
PD Input Resistance
Power Down “ON”
<100
>50
VCC
Power Down “OFF”
0
ns
kΩ
V
V
Threshold voltage
Threshold voltage
MODULATORS AND
UPCONVERTERS
5
Rev B1 010329
5-9
RF2412
Pin
1
Function
VDD2
2
VDD1
3
PD
MODULATORS AND
UPCONVERTERS
5
4
5
I SIG
I REF
6
Q REF
7
Q SIG
8
GND
9
GND
5-10
Description
Supply Voltage for the RF Output Stage only. A 33pF external bypass
capacitor is required, and an optional 0.1µF will be required if no other
low frequency bypass capacitors are nearby. The trace length between
the pin and the bypass capacitors should be minimized. The ground
side of the bypass capacitors should connect immediately to ground
plane. Though the part is designed to run from a 5V supply, it will also
work at 4V. Gain and available output power will be reduced by 5dB to
10dB. Pins 1 and 2 may share a common bypass capacitor.
Supply Voltage for all circuits but the RF Output Stage. The same comments as for VDD2 apply to this pin. Pins 1 and 2 may share a common
bypass capacitor.
Power Down control. When this pin is 0V all circuits are turned off, and
when connected to VDD, all circuits are operational. This is a high
impedance input, internally connected to the parallel gates of two
switching FETs. To minimize current consumption in power down
mode, this pin should be as close to 0V as possible. Turn-on voltage of
some parts of the circuit may be as low as 0.1V. In order to maximize
output power, the voltage on this pin should be as close to VDD as possible during normal operation. A 33pF capacitor is recommended for
bypassing. If this pin is not used for power down control, it may be tied
to pins 1 and 2, and all three pins may share one 33pF capacitor, provided that the associated trace lengths are minimized.
Baseband input to the I mixer. This pin is DC coupled. Maximum output
power is obtained when the input signal has a peak to peak amplitude
of 5V. A DC reference of approximately VDD/2 must be supplied to this
pin. The input impedance of this pin is about 3kΩ. The SIG and REF
inputs are inputs of a differential amplifier. Therefore, the REF and SIG
inputs are interchangeable. If swapping the I SIG and I REF pins, the
Q SIG and Q REF pins also need to be swapped to maintain the correct
phase. The SIG and REF pins may be driven differentially to increase
conversion gain.
Reference voltage for the I mixer. This voltage should be the same as
the DC voltage supplied to the I SIG pin. To obtain a carrier suppression of better than 25dB it may be tuned ± 0.15V (relative to the I SIG
DC voltage). Without tuning, the carrier suppression will typically be
better than 25dB. The input impedance of this pin is about 3kΩ.
Reference voltage for the Q mixer. This voltage should be the same as
the DC voltage supplied to the Q SIG pin. To obtain a carrier suppression of better than 25dB it may be tuned ±0.15V (relative to the Q SIG
DC voltage). Without tuning, the carrier suppression will typically be
better than 25dB. The input impedance of this pin is about 3 kΩ.
Baseband input to the Q mixer. This pin is DC coupled. Maximum output power is obtained when the input signal has a peak to peak amplitude of 5V. A DC reference of approximately VDD/2 must be supplied to
this pin. The input impedance of this pin is about 3 kΩ. Therefore, the
REF and SIG inputs are interchangeable. If swapping the I SIG and I
REF pins, the Q SIG and Q REF also need to be swapped to maintain
the correct phase. The SIG and REF pins may be driven differentially to
increase conversion gain.
Ground connection. Keep traces physically short and connect immediately to ground plane for best performance.
Same as pin 8.
Interface Schematic
VDD1
VDD2
PD
I SIG
I REF
Same as pin 5.
Same as pin 4.
Rev B1 010329
RF2412
Function
LO1
11
MOD OUT+
12
13
14
MOD OUTGND
MIX IN-
15
16
17
MIX IN+
GND
LO2
Description
Interface Schematic
High impedance modulator LO input. If approximately 0dBm of LO
LO1
power is available, a shunt 56Ω resistor may be used for matching. If
the available LO power is approximately -6dBm, then a reactive match
may be required. There is an internal blocking capacitor between this
pin and the LO circuitry, but not between the pin and an internal resistor
to ground (see the functional block diagram). An external blocking
capacitor should be provided if the pin is connected to a device with DC
present. A DC path to ground (an inductor or resistor to ground) is,
however, acceptable at this pin. If a blocking capacitor is required, a
value of 1nF is recommended.
Balanced IF output port. If no filtering is required this pin can be connected directly to the MIX IN+ pin. This pin is NOT DC blocked and carries DC. A blocking capacitor of 1nF is needed when this pin is
connected to a DC path. An appropriate matching network may be
needed if an IF filter is used.
Same as pin 11, except complementary output.
See pin 11.
5
Same as pin 8.
High impedance balanced input to the IF stage. This pin has an internal
DC blocking capacitor. If no IF filter is needed this pin may be connected directly to MOD OUT-. If an IF filter is used, an external shunt
resistor to ground may be needed to provide correct matching for the
filter.
Same as pin 14, except complementary input.
MIX IN+
MIX IN-
BIAS
GND
GND
RF OUT
BIAS
See pin 14.
Same as pin 8.
Mixer LO Input port. A shunt 56Ω resistor can be used for matching.
This pin has internal DC blocking,
LO2
BIAS
18
19
20
MOD OUT+
MOD OUT-
BIAS
Same as pin 8.
Same as pin 8.
50Ω output. This pin is not internally DC blocked, and an external
blocking capacitor of 33pF is required.
RF OUT
Rev B1 010329
5-11
MODULATORS AND
UPCONVERTERS
Pin
10
RF2412
Application Schematic
915 MHz Operation, DC Coupled I and Q Inputs
VDD
100 nF
33 pF
1
RF OUT
20
33 pF
POWER
CONTROL
19
3
18
4
17
5
5
16
MODULATORS AND
UPCONVERTERS
2
6
15
7
14
8
13
33 pF
I SIG
VREF
33 pF
56 Ω
Σ
100 nF
Q SIG
9
LO1 IN
12
-45°
1 nF
+45°
11
10
56 Ω
Application Schematic
915 MHz Operation, AC Coupled I and Q Inputs
VDD
100 nH
33 pF
1
33 pF
2
100 nF
4
17
100 Ω
5
16
100 Ω
6
15
7
14
8
13
33 pF
33 pF
100 nF
100 nF
19
18
100 Ω
VREF
POWER
CONTROL
3
I SIG
RF OUT
20
LO2 IN
56 Ω
Σ
100 Ω
Q SIG
9
1 nF
LO1 IN
-45°
12
+45°
10
11
56 Ω
5-12
Rev B1 010329
RF2412
Evaluation Board Schematic
(Download Bill of Materials from www.rfmd.com.)
C5
100 pF
C1
33 pF
2
ISIG
J1
QSIG
J2
LO1 IN
J3
C2
33 pF
50 Ω µstrip
C3
1 nF
3
18
4
17
16
5
Σ
6
15
7
14
8
13
9
RF OUT
J5
19
50 Ω µstrip
-45°
+45°
C4
100 pF
50 Ω µstrip
LO2 IN
J4
R2
56 Ω
5
FOR 50 Ω MATCH
12
11
10
P1
R1
56 Ω
FOR 50 Ω MATCH
Rev B1 010329
POWER
CONTROL
50 Ω µstrip
P1-3
50 Ω µstrip
20
1
MODULATORS AND
UPCONVERTERS
P1-1
2412400 Rev -
P1-1
P1-3
1
VCC
2
GND
3
REF
5-13
RF2412
Evaluation Board Layout
1.52” x 1.52”
MODULATORS AND
UPCONVERTERS
5
5-14
Rev B1 010329
RF2412
Pout vs. Baseband Modulation Frequency
Pout vs. Baseband Modulation Voltage
5
20
Upper Side Band
BB: 54.5dBmV
LO1: 70 MHz, 0 dBm, 56 Ω Res. Term.
LO2: 845 MHz, 0 dBm, 56 Ω Res. Term.
Vdd: 5.0V, Vref=2.5V
+25C
-40C
-40C
+85C
+85C
0
0
Pout (dBm)
-10
-5
-10
Upper Side Band
BB: 100 kHz
LO1: 70 MHz, 0 dBm, 56 Ω Res. Term.
LO2: 845 MHz, 0 dBm, 56 Ω Res. Term.
Vdd: 5.0V, Vref=2.5V
-20
-30
10
20
30
40
50
45
60
50
Modulation Frequency (MHz)
60
65
Pout vs. LO1 Power
20
20
Upper Side Band
BB: 100 kHz, 54.5dBmV
LO1: 0 dBm, 56 Ω Res. Term.
LO2: 845 MHz, 0 dBm, 56 Ω Res. Term.
Vdd: 5.0V, Vref=2.5V
10
Upper Side Band
BB: 100 kHz, 54.5 dBmV
LO1: 70 MHz, 56 Ω Res. Term.
LO2: 845 MHz, 0 dBm, 56 Ω Res. Term.
Vdd: 5.0V, Vref=2.5V
+25C
-40C
10
+85C
0
Pout (dBm)
Pout (dBm)
55
Modulation Voltage (dBmV)
Pout vs. LO1 Frequency
-10
-20
+25C
-40C
+85C
0
-10
-20
-30
-30
0
50
100
150
200
250
300
-10
-8
-6
LO1 Frequency (MHz)
Pout vs. LO2 Frequency
10
-2
0
2
4
6
Pout vs. LO2 Power
20
Upper Side Band
BB: 100 kHz, 54.5dBmV
LO1: 70 MHz, 0 dBm, 56 Ω Res. Term.
LO2: 0 dBm, 56 Ω Res. Term.
Vdd: 5.0V, Vref=2.5V
Upper Side Band
BB: 100 kHz, 54.5 dBmV
LO1: 70 MHz, 0 dBm, 56 Ω Res. Term.
LO2: 845 MHz, 56 Ω Res. Term.
Vdd: 5.0V, Vref=2.5V
+25C
-40C
10
+85C
Pout (dBm)
0
-10
-20
-30
100
-4
LO1 Power (dBm)
20
Pout (dBm)
5
-15
0
MODULATORS AND
UPCONVERTERS
Pout (dBm)
10
+25C
+25C
-40C
+85C
0
-10
-20
-30
400
700
1000
1300
LO2 Frequency (MHz)
Rev B1 010329
1600
1900
-10
-8
-6
-4
-2
0
2
4
6
LO2 Power (dBm)
5-15
RF2412
Phase Error vs. LO1 Frequency
Suppression Levels vs. LO1 Frequency
(+25C)
10.0
0
-IMD3
-IMD2
S.B.
CARR
+IMD2
+IMD3
-20
Suppression Level (dBc)
Phase Error (Deg.)
5.0
0.0
-5.0
5
Upper Side Band
BB: 100 kHz, 54.5dBmV
LO1: 0 dBm, 56 Ω Res. Term.
LO2: 845 MHz, 0 dBm, 56 Ω Res. Term.
Vdd: 5.0V, Vref=2.5V
-60
+25C
Upper Side Band
BB: 100 kHz, 54.5dBmV
LO1: 0 dBm, 56 Ω Res. Term.
LO2: 845 MHz, 0 dBm, 56 Ω Res. Term.
Vdd: 5.0V, Vref=2.5V
-80
-40C
+85C
-10.0
-100
0
MODULATORS AND
UPCONVERTERS
-40
50
100
150
200
250
300
0
50
LO1 Frequency (MHz)
250
300
0
1.5
+25C
-IMD3
-IMD2
S.B.
-40C
CARR
+IMD2
+IMD3
-20
+85C
Suppression Level (dBc)
1.0
Amplitude Error (dB)
200
Suppression Levels vs. LO1 Frequency
(-40C)
2.0
0.5
0.0
-0.5
-1.0
Upper Side Band
BB: 100 kHz, 54.5dBmV
LO1: 0 dBm, 56 Ω Res. Term.
LO2: 845 MHz, 0 dBm, 56 Ω Res. Term.
Vdd: 5.0V, Vref=2.5V
-1.5
-40
-60
Upper Side Band
BB: 100 kHz, 54.5dBmV
LO1: 0 dBm, 56 Ω Res. Term.
LO2: 845 MHz, 0 dBm, 56 Ω Res. Term.
Vdd: 5.0V, Vref=2.5V
-80
-2.0
-100
0
50
100
150
200
250
300
0
50
LO1 Frequency (MHz)
Pout and Idd vs. Vdd
Upper Side Band
BB: 100 kHz, 54.5dBmV
LO1: 70 MHz, 0 dBm, 56 Ω Res. Term.
LO2: 845 MHz, 0 dBm, 56 Ω Res. Term.
Vref=2.5V
40
-20
20
-80
0
-100
Idd (mA)
-10
Pout, +25C
Pout, -40C
Pout, +85C
Idd, +25C
Idd, -40C
Idd, +85C
-30
5.0
5.5
Vdd (Volts)
250
300
6.0
6.5
-IMD3
-IMD2
S.B.
CARR
+IMD2
+IMD3
-20
Suppression Level (dBc)
80
60
4.5
200
0
0
4.0
150
Suppression Levels vs. LO1 Frequency
(+85C)
100
10
100
LO1 Frequency (MHz)
20
Pout (dBm)
150
LO1 Frequency (MHz)
Amplitude Error vs. LO1 Frequency
5-16
100
-40
-60
Upper Side Band
BB: 100 kHz, 54.5dBmV
LO1: 0 dBm, 56 Ω Res. Term.
LO2: 845 MHz, 0 dBm, 56 Ω Res. Term.
Vdd: 5.0V, Vref=2.5V
0
50
100
150
200
250
300
LO1 Frequency (MHz)
Rev B1 010329
RF2412
Optimized Carrier Suppression vs. LO1 Frequency
(optimized at +25C and LO1=70 MHz)
0
Upper Side Band
BB: 100 kHz, 54.5dBmV
LO1: 0 dBm, 56 Ω Res. Term.
LO2: 845 MHz, 0 dBm, 56 Ω Res. Term.
Vdd: 5.0V, Vref=2.5V
Carrier Suppression (dBc)
-20
-40
+25C
-60
-40C
+85C
5
-80
50
100
150
200
250
300
MODULATORS AND
UPCONVERTERS
0
LO1 Frequency (MHz)
Optimized Sideband Suppression vs. LO1 Frequency
(optimized at +25C and LO1=70 MHz)
Sideband Suppression (dBc)
0
Upper Side Band
BB: 100 kHz, 54.5dBmV
LO1: 0 dBm, 56 Ω Res. Term.
LO2: 845 MHz, 0 dBm, 56 Ω Res. Term.
Vdd: 5.0V, Vref=2.5V
-20
-40
+25C
-60
-40C
+85C
-80
0
50
100
150
200
250
300
LO1 Frequency (MHz)
Rev B1 010329
5-17