346C Series

Multi-Octave 10 Bit Digital PIN Diode Attenuators (0.5-18 GHz)

SERIES 346C

The 346C Series is a family of nonreflective PIN diode attenuators, each programmable to 60 dB in attenuation steps as low as 0.06 dB, and covering the frequency range from 0.5 GHz to 18 GHz in four overlapping multi-octave bands.

Each model in the Series comprises an integrated assembly of a dual (current-controlled) PIN diode attenuator, and a driver circuit consisting of a D/A converter and a voltage-to-current converter.  (See Figure 1 below)

The RF circuit consists of two wide-band, T-pad attenuator sections in tandem. The levels of series and shunt currents required to maintain a bilateral match at all attenuation levels are provided by the driver.

This arrangement assures monotonicity over the operating band at all levels of attenuation and for any programmed attenuation step.


 

  • Frequency range: 0.5 GHz-18GHz
  • in four overlapping ranges
  • Attenuation range: 60 dB
  • Programming:, 10-Bit binary
  • LSB: 0.06 dB
  • Monotonicity: guaranteed



PERFORMANCE CHARACTERISTICS
CHARACTERISTIC MODEL 3460C MODEL 3461C MODEL 3462C MODEL 3468C
Frequency Range (GHz) 0.5-4 0.5-8 2-8 2-18
Mean Attenuation Range (dB) 60 60 60 60
Insertion Loss (dB) (max) 2.5 2.5 (0.5-4 GHz)
3.0 (4-8 GHz)
3.0 4.5
VSWR (max) 1.8 1.8 1.8 2.0
Flatness up to 20 dB        
40 dB        
60 dB        
±0.5 dB
±0.75 dB
±1.0 dB
±0.75 dB
±1.0 dB
±1.5 dB
±0.75 dB
±1.0 dB
±1.5 dB
±1.0 dB
±1.25 dB
±3.0 dB

Accuracy of Attenuation
0 to 20 dB ± 1.0 dB
20 to 40 dB ± 1.5 dB
40 to 60 dB ± 2.0 dB
Monotonicity
Guaranteed
Phase Shift
See figure 2
Temperature Coefficient
± 0.02 dB/ °C
Power Handling Capability
Without Performance Degradation
All Units
Up to 50 mW cw or peak (see figure 3)
Survival Power
All units
2 W average or peak,
from -65(°)C to +25(°)C
(see figure 4 for higher
temperatures).
Switching Time
ON Time 1.0 µsec. max.
OFF Time 0.5 µsec. max.
Programming Positive true binary. For complementary code, specify Option 2. To interface with other logic families, please contact factory.
Minimum Attenuation Step 0.06 dB
Logic Input
Logic "O" (Bit OFF) -0.3 to +0.8V
Logic"1" (Bit ON) +2.0 to +5.OV
Input Current 1O µA max.

Nominal Control Voltage Characteristics

    Range 0 to 2 mA
 
    Transfer Function 30 dB / mA
 
    Input Impedance
3 kohms

 
Power Supply Requirements +12V to +15V, 80 mA
-12V to -15V, 60 mA

 
Power Supply Rejection Less than 0.1 dB / volt change in either supply
 

ENVIRONMENTAL RATINGS
Operating Temperature Range
-54°C to + 110°C
Non-Operating Temperature Range
-65°C to + 125°C
Humidity
MIL-STD-202F, Method 103B, Cond. B (96 hrs. at 95%)
Shock
MIL-STD-202F, Method 213B, Cond. B (75G, 6 msec)
Vibration
MIL-STD-202F, Method 204D, Cond. B (.06" double amplitude or 15G, whichever is less)
Altitude
MIL-STD-202F, Method 105C, Cond. B (50,000 ft.)
Temp. Cycling
MIL-STD-202F, Method 107D, Cond. A, 5 cycles

PIN NO.
J3 PIN FUNCTIONS
     1
     2
     3
     4
     5
     6
     7
     8
     9
     10
     11
     12
     13
     14
     15
     GND (Note 2)
     ANALOG INPUT(Note 3)
     0.13 dB
     GND
     0.25 dB
     0.5 dB
     1dB
     2dB
     4dB
     8dB
     16dB
     32 dB(MSB)
     +V
     -V
     0.06 dB(LSB)

AVAILABLE OPTIONS
Option No. Description
2
Complementary programming
(logic "O" is bit on)
7
Two SMA male rf connectors
10
One SMA male (J1) and one SMA female (J2) rf connector




 

ACCESSORY FURNISHED
Mating power/logic connector

(1)  All unused logic inputs must be grounded.

(2)  For normal programming control Pin 1 must be grounded or at logic "O" . Application of logic "l " to Pin 1 overrides the digital input and sets the unit to insertion loss. For units with complementary programming (Option 2), the application of a logic "1" to Pin I sets the unit to high isolation (60 dB or greater).

(3)  Pin 2 is available to (a) monitor the D/A converter output, (b) apply a modulation signal from a current source, or (c) apply an independent analog signal for turn-on, turn-off or vernier attenuation levels.*

(4)  The Series 346C attenuators are 10-bit digital attenuators. In order to use this device with a lesser number of bits (lower resolution), the user may simply ground the logic pins for the lowest order unused bits. For example, a Series 346C unit oper - ated as an 8-bit unit would have Pin 15 and Pin 3 connected to ground. All other parameters remain unchanged.

* If not used as descrubed in A, B or C, pin 2 must be open.



Dimensional Tolerances, unless otherwise indicated: XX ± .02; XXX ± .005