Series 349 and 349H Octave-Band 11 Bit Digital PIN Diode Attenuators

  Contact Us        

Application Notes for Microwave Attenuator

 

The Series 349 and 349H programmable attenuators provide greater than octave-band performance and wide programming flexibility in compact rugged packages. Attenuation ranges up to 80 dB are available with attenuation increments as low as 0.03 dB.

Each Series 349 and 349H unit is an integrated assembly of a balanced PIN diode attenuator and a driver circuit consisting of a PROM, a D/A converter and a current-to-voltage converter. See Figure 1. This arrangement provides a high degree of accuracy and repeatability and preserves the inherent monotonicity of the attenuator.

SERIES 349
The maximum programmable attenuation range in every band except the 8.0–18.0 GHz frequency range is 80 dB. Attenuators limited in range to 64 dB exhibit switching times less than 500 nsec while the 80 dB units switch in less than 2 µsec.

SERIES 349H
If even faster switching of 64 dB units is required,
GMC offers its Series 349H attenuators. These units switch in less than 300 nsec with essentially the same performance specifications as the 64 dB Series 349 units.
All the attenuators are available with either a strobe/ latch or a non-linear current or voltage controlled attenuation capability. Refer to the Available Options table and the Notes following the Pin Functions table.

Series 349 and 349H attenuator block diagram

 

  • Absorptive
  • 64 or 80 dB range
  • .03 dB resolution
  • Binary or BCD programming
  • Guaranteed monotonicity
  • Frequency range: 0.75 to 18 GHz

Series 349 octave-band digital PIN diode attenuator

 

PERFORMANCE CHARACTERISTICS: SERIES 349

MODEL FREQUENCY
RANGE
GHZ
MAX.
INSERTION
LOSS(dB)
MAX.
VSWR
MAX. FLATNESS (±dB)
AT MEAN ATTENUATION LEVELS
UP TO
10 dB 20 dB 40 dB 60 dB (4) 80 dB(1)
3491-64
3491-80
1.0 - 2.0 1.6 1.5 0.3 0.8 1.5 1.6 1.9
0.75 - 2.25(2) 1.7 2.0 0.5 1.4 3.0 3.5 3.8
3492-64
3492-80
2.0 - 4.0 1.8 1.5 0.3 0.8 1.5 1.6 1.9
1.5-4.5(2) 1.9 2.0 0.5 1.4 3.0 3.5 3.8
3493-64
3493-80
2.6-5.2 2.0 1.6 0.3 0.8 1.5 1.6 1.9
1.95-5.85(2) 2.1 2.1 0.5 1.4 3.0 3.5 3.8
3494-64
3494-80
4.0 - 8.0 2.4 1.7 0.3 0.8 1.5 1.6 1.9
3.0-9.0(2) 2.5 2.2 0.5 1.4 3.0 3.5 3.8
3495-64
3495-80
5.0 - 10.0 2.6 1.7 0.5 0.9 1.5 1.6 1.9
3.75 - 11.25(2) 2.7 2.2 0.7 1.4 3.0 3.5 3.8
3496-64
3496-80
6.0-12.0 2.7 1.8 0.7 1.0 1.5 1.6 1.9
4.5-13.5(2) 2.8 2.2 0.9 1.5 3.0 3.5 3.8
3498-64 8.0-18.0 3.0(3) 1.8(3) 0.7 1.0 1.5 1.6 -
6.0-18.0(2) 3.0(3) 1.8(3) 0.9 1.5 3.0 3.5 -

.

.

PERFORMANCE CHARACTERISTICS: SERIES 349H

MODEL FREQUENCY
RANGE
GHZ
MAX.
INSERTION
LOSS(dB)
MAX.
VSWR
MAX. FLATNESS (±dB)
AT MEAN ATTENUATION LEVELS
UP TO
10 dB 20 dB 40 dB 60 dB (4)  
3491H-64

1.0 - 2.0 1.6 1.5 0.5 1.0 1.5 1.6  
0.75 - 2.25(2) 1.7 2.0 0.7 1.6 3.0 3.5  
3492H-64

2.0 - 4.0 1.8 1.5 0.5 1.0 1.5 1.6  
1.5-4.5(2) 1.9 2.0 0.7 1.6 3.0 3.5  
3493H-64

2.6-5.2 2.0 1.6 0.5 1.0 1.5 1.6  
1.95-5.85(2) 2.1 2.1 0.7 1.6 3.0 3.5  
3494H-64

4.0 - 8.0 2.4 1.7 0.5 1.0 1.5 1.6  
3.0-9.0(2) 2.5 2.2 0.7 1.6 3.0 3.5  
3495H-64

5.0 - 10.0 2.6 1.7 0.7 1.0 1.5 1.6  
3.75 - 11.25(2) 2.7 2.2 0.9 1.6 3.0 3.5  
3496H-64

6.0-12.0 2.7 1.8 0.7 1.0 1.5 1.6  
4.5-13.5(2) 2.8 2.2 0.9 1.6 3.0 3.5  
3498H-64 8.0-18.0 3.0(3) 1.8(3) 0.7 1.0 1.5 1.6  
6.0-18.0(2) 3.0(3) 1.8(3) 0.9 1.6 3.0 3.5  

 

 

  Mean Attenuation Range
       349(X), 349(X)H-64.................  64 dB
       349(X)-80................................  80 dB
     
  Accuracy of Attenuation
     0 to 30dB............................... ± 0.5 dB
     > 30 to 50 dB......................... ± 1.0 dB
     > 50 to 64 dB......................... ± 1.5 dB
   > 64 to 80 dB......................... ± 2.0 dB
     
  Monotonicity.........................
Guaranteed
     
  Phase Shift.............................
See Application Notes
     
  Temperature Coefficient........
± 0.025 dB/ °C
     
Power Handling Capability
     Without Performance
      Degradation
 

 

            3491, 3492H thru 3498H...  10 mW cw or peak

            3491H...........................  1 mW cw or peak

            All other units ................  100 mW cw or peak
     
Survival Power
    from -40°C to +25°C;
   (see Figure 2 for Higher Temperatures).............


1W average, 25W peak (1
µsec max pulse width)
     
     series 349 and 349H power derating factor  
     
  Switching Time  
           349(X)H-64.........................  300 nsec max.
           349(X)-64...........................  550 nsec max.
           349(X)-80...........................  2 μsec max.
     
  Programming..........................
Positive true binary (standard) or BCD (Option 1). For complementary code, specify
Option 2.
     
  Minimum Attenuation Step(5)... 0.25 dB
      Binary Units  
            349(X)-64, 349(X)H-64....  0.03 dB
            349(X)-80.......................  0.04 dB
      BCD Units.............................  0.10 dB
     
Logic Input
     Logic "0" (Bit OFF).................. -0.3 to +0.8V
     Logic "1" (Bit ON)................... +2.0 to +5.0V
     Logic Input Sink Current..........  0.3 mA max
     Logic Input Source Current.......  3 µA max
     
Analog Input (6)
     349(X)-64, 349(X)H-64.............. 0 to 6.4V(7)
     349(X)-80................................ 0 to 8V(8) 
     Input Resistance................... 10K ± 20% Ohms
     
  Power Supply
   Requirements
......................

+12 to +15V, 120mA
    -12 to -15V, 50mA
     
   Power Supply
   Requirements
.....................
 Less than 0.1 dB/volt change in either supply
     

 

 (1) Applicable only to 80 dB versions.
 (2) Specifications for the extended frequency ranges are typical.
 (3) Except from 16-18 GHz where insertion loss is 4.2 dB max. and VSWR is 2.2.
 (4) Flatness specification at 64 dB level is ±0.2 dB higher than at 60 dB.

 (5)  The Series 349 attenuators are 11-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 349 unit operated as an 8-bit unit would have Pin 15, Pin 1 and Pin 2 connected to ground. All other parameters remain unchanged.

 (6) Switching speed for analog input is 100 µsec. typical. With Option G06 it is not greater than with digital input.

 (7)  For average attenuation of 64 dB the analog voltage is in the range of 4 to 8 V.

 (8)  For average attenuation of 80 dB the analog voltage is in the range of 6 to 10 V

 

OPTION (G09)ENVIRONMENTAL RATINGS

 Operating Temperature
   Range....................... -40°C to +85°C
 Non-Operating Temperature
   Range....................... -54°C to +100°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
 
ACCESSORY FURNISHED
Mating power/logic connector
 
AVAILABLE OPTIONS
Option No. Description
1
BDC programming (Binary is standard)
2
Complementary programming
(logic “0” is Bit ON)
4

Strobe latch for data input. Attenuator responds to data input when logic “0” is applied. Attenuator latched to data input when logic “1” is applied. See Fig. 3

 G06
Switching speed for analog input is no
longer than with a digital input
 7
Two SMA male RF connectors
 10 One SMA male RF connector (J1) and one SMA female RF connector (J2)
 G09 Meeting the specified Environmental Ratings
G12 RoHS Compliant
G16 RoHS Plus REACH Compliant

 

                                                 DIMENSIONS AND WEIGHTS

 

  MODEL DIM “A” DIM “B” DIM “C” DIM “D” DIM “E” DIM “F”
   3491,
3491H

 .58
(14,7)
 .42
(10,7)
 2.56 ± .03
(65,0)
 .56
(14,2)
 1.53
(38,9)
 .34
(8,6)
   3492, 93,
3492H, 93H
 .30
(7,6)
 .14
(3,6)
 2.00 ± .03
(50,8)
 .50
(12,7)
 1.29
(32,8)
 .34
(8,6)
   3494, 95, 96
3494H, 95H, 96H
 .30
(7,6)
 .14
(3,6)
 2.00 ± .03
(50,8)
 .75
(19,1)
 1.19
(30,2)
 .34
(8,6)
   3498,
3498H
 .30
(7,6)
 .14
(3,6)
 2.00 ± .03
(50,8
 .75
(19,1)
 1.00
(25.4)
 .34
(8,6)


NOTES
1. The Series 349 attenuators are 11-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 349 unit operated as an 8-bit unit would have Pin 15, Pin 1 and Pin 2 connected to ground. All other parameters remain unchanged.
2. Normally supplied as an Analog input. Leave pin open if analog input is not used. Optionally available as a strobe latch function for input data.
3. Pin 3 is available to apply a current or voltage to control the attenuator in a non-linear fashion.
4. lt is recommended that when operating the Series
349/H Attenuators with the Strobe/Latch Option -4 feature, the digital control inputs should be in place, with the Latch set to a low “(0)” level, before the Attenuator is powered up.

Dimensional Tolerances, unless otherwise indicated: .XX ±.02; .XXX ±.008