Kratos Microwave Israel

Full Line Product Catalog

Microwave Attenuator Series 348 and 348H

Application Notes for Microwave Attenuators

The Series 348 and 348H Digitally Programmable Attenuators provide greater than octave band performance in small hermetic packages ideally suitedfor high reliability applications. The Series 348 offers moderate power handling capability (100 mW) at switching speeds less than 500 nsec while the 348H Series offers 200 nsec switching speed at lower power Attenuation of all units is 60 dB with monotonic 0.25 dB step resolution.

The attenuator is an integrated assembly of a sealed RF Microwave Integrated Circuit assembly and a sealed hybrid driver. Attenuation is controlled via a miniature 14 pin connector. See Fig. 1.

Although these units are primarily intended for use as digital attenuators, they can also be used as analog (voltage driven) attenuators or as combination analog/digital attenuators. (See note 4 below)

 

  • 2 to 18 GHz
  • Digital/Analog
  • 8 Bit TTL
  • Hermetically sealed
  • Miniature
Microwave attenuator series 348 - Kratos General Microwave 
              Model 3484
Series 348 and 348H attenuator block diagram    Model 3488 typical phase vs attenuation and frequency          

PERFORMANCE CHARACTERISTICS

MODEL FREQUENCY RANGE (GHz) MAX. INSERTION LOSS (dB) MAX. VSWR
FLATNESS (± dB)
AT MEAN ATTENUATION LEVELS UP TO
10 dB 20 dB 40 dB 60 dB
3482/H* 2.0 - 4.0 1.8 1.5 0.5 1.0 1.5 1.6
1.5 - 4.5(1) 1.9 2.0 0.7 1.6 3.0 3.5
3483*/H* 2.6 - 5.2 2.0 1.6 0.5 1.0 1.5 1.6
1.95 - 5.85(1) 2.1 2.1 0.7 1.6 3.0 3.5
3484/H 4.0 - 8.0 2.4 1.7 0.5 1.0 1.5 1.6
3.0 - 9.0(1) 2.5 2.2 0.7 1.6 3.0 3.5
3486/H 6.0 - 12.0 2.7 1.8 0.7 1.0 1.5 1.6
4.5 - 13.5(1) 2.8 2.2 0.9 1.6 3.0 3.5
3488/H 8.0 - 18.0 3.0(2) 1.8(3) 0.7 1.0 1.5 1.6
6.0 - 18.0(1) 3.0(2) 1.8(3) 0.9 1.6 3.0 3.5
* Special-order product. Consult factory before ordering. 
(1) Specifications for the extended frequency ranges are typical.
(2) For 3488, 4.0 dB from 16-18 GHz. For 3488H, 3.5 dB from 12-16 GHz and 4.0 dB from 16-18 GHz.
(3) VSWR is 2.0 from 16-18 GHz.
Mean Attenuation Range..........................
60 dB
Accuracy of Attenuation
   0 to 30dB.............................................. ± 0.5 dB
   > 30 to 50 dB......................................... ± 1.0 dB
   > 50 to 60 dB......................................... ± 1.5 dB
Monotonicity............................................
Guaranteed
Phase Shift...............................................
See Application Notes
Temperature Coefficient............................
± 0.02 dB/°C

Power Handling Capability 
   Without Performance Degradation..........

(348) 100 mW cw or peak
(348H) 10 mW cw or peak

Survival Power
   (from -55°C to +25°C; see Figure 3 for
   Higher Temperatures).............................
1W average, 25W peak
Switching Time......................................... (348) 500 nsec max
(348H) 200 nsec max
Programming: 8 Bit TTL............................
Positive True binary
Minimum Attenuation Step....................... 0.25 dB
Logic Input
   Logic "0"................................................. -0.3 to +0.8V
   Logic "1"................................................. +2.0 to +5.0V
   Logic Input Current................................ 10 µA max
Analog Input Characteristics
   Range..................................................... 0 to 6V
   Transfer Function.................................... 10 dB/V
   Input Resistance...................................... 6 kohms
Power Supply Requirements.......................
+12 to +15V, 120mA
  -12 to -15V, 50 mA
OPTION (G09) ENVIRONMENTAL RATINGS
Operating Temperature Range................ -54°C to +110°C
Non-Operating Temperature Range........ -65°C to +125°C
ACCESSORY FURNISHED
Mating power/logic connector
AVAILABLE OPTIONS
                        Option No. Description
7
Two SMA male RF connectors
10
One SMA male (J1) and one SMA female (J2) RF connector
49

High Rel screening (see Table 1 below for further information)

 G09 Guaranteed to meet Environmental Ratings
 G12 RoHS Compliant
G18 REACH Compliant
 
Table 1. Option 49 High Rel Screening - MIL - STD 883

TEST METHOD CONDITION
Internal Visual 2017
Temperature Cycle 1010 A
Mechanical Shock 2002 B
Burn-In 1015
Leak 1014 A1

                                                  DIMENSIONS AND WEIGHT

Series 348 and 348H attenuator dimensions and weight diagram

                                                                      SERIES 348/H
                                                             wt: 2.4 oz. (68 gr) approx.

Dimensions are stated in inches (mm).  Tolerances, unless otherwise indicated: .XX ±.02; .XXX ±.008

 J3 POWER/LOGIC CONNECTIONS
PIN 
FUNCTIONS (Note 1)
 A  Digital/Power GND
 B  Logic Control (Note 2)
 C  –12 to –15V
 D  0.25 dB (LSB)
 E  0.5 dB
 F  1 dB
 H  4 dB
 J  2 dB
 K  16 dB
 L  32 dB (MSB)
 M  +12 to +15V
 N  8 dB
 P  GND
 R  Analog Input (Notes 3&4)

NOTES

(1) All unused logic inputs must be grounded.
(2) For normal TTL programming control, PIN B must be grounded or at Logic 0. Application of Logic 1 to PIN B overrides the digital input and sets the unit to insertion loss. To interface with other logic families (e.g., CMOS, MTL, NMOS, etc.) contact factory.
(
3) If Analog input is not to be used, then connect PIN R to PIN P.
(4) To use the unit as a voltage controlled attenuator, apply a control voltage of 0 to +6V at PIN R. The slope of attenuation will be nominally 10 dB/V. For a non-zero source resistance (RO) of up to 500 ohms, the attenuation error is approximately –.0017 • RO • VIN dB and the slope will decrease by approximately 0.17 dB/V per 100 ohms of source resistance. Using the 348/H Series attenuator as both a digital and analog control attenuator, the total attenuation ATT = 10 • VIN + programmed digital attenuation. The maximum attainable mean attenuation is 60 dB.

 
 


The information contained in this data sheet is basic marketing information and does not contain any export controlled information.