346C Series Multi-Octave 10 Bit Digital PIN Diode Attenuators

  Contact Us         Application Notes for Microwave Attenuators 

 

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

 

 

346C series multi-octave 10 bit digital PIN diode attenuator

 3460C

 

 

 

 

 

 

The 346C Series is a family of Non-reflective 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.

Series 346C attenuator block diagram

 

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)
3.2 (4-8 GHz)
3.2 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

 

*Special-order product. Consult factory before ordering.

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 Application Notes
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(1)

Logic Input
   Logic "0" (Bit OFF) ....................... -0.3 to +0.8V
   Logic"1" (Bit ON) ........................... +2.0 to +5.0V
   Input Current ................................... 10 µA max.

Nominal Control Voltage Characteristics
    Range.................................. 0 to 3 mA
    Transfer Function............... 20 dB / mA
    Input Impedance..................
3 kohm
Power Supply
    Requirements
......................


+12V ±5%, 90 mA
-12V ±5%, 60 mA
Power Supply
     Rejection
............................


Less than 0.1 dB / volt change in either supply
  1. 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 operated as an 8-bit unit would have Pin 15 and Pin 3 connected to ground. All other parameters remain unchanged.
 
 
series 346C maximum peak and average operating power without performance degradation model 346C attenuator survival power derating factor
   
 
OPTION (G09) 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

 

 

DIMENSIONS AND WEIGHT

Series 346C attenuator dimensions and weight diagram
SERIES 346C
Wt: 3 0z. (85 gm) approx
.


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

 
AVAILABLE OPTIONS
Option No.      Description
2
Complementary programming
(logic "0" is bit on)
7
Two SMA male RF connectors
10
One SMA male (J1) and one SMA female (J2) RF connector
 62 ±15V Operation
C38

30 dB attenuation range. Consult factory for impact on specifications.

G09 Guaranteed to meet Environmental Ratings.

 G12

 RoHS Compliant
G16  RoHS Plus REACH Compliant
 Z06  1 to 18 GHz operation. I.L 4.8dB max. (Model 3468C)
   
 
   
  ACCESSORY FURNISHED
  Mating power/logic connector
   
   
   
 
 PIN NO.   J3 PIN FUNCTIONS(1)(4)
             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)


 

NOTES

(1)  All unused logic inputs must be grounded.

(2)  For normal programming control Pin 1 must be grounded or at logic "0" . Application of logic "1" 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 1 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. If not used as described in (a), (b) or (c). Pin 2 must be open. 

(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.