Data Sheet SHF C981 A
SHF Communication Technologies AG

Data SheetSHF C981 A

Tunable Filter

SHF reserves the right to change specifications and design without notice
V001 - Feb. 27, 2024 - Page 1

Data Sheet SHF C981 A
SHF Communication Technologies AGDescription
The SHF C981 A is a RoHS compliant tunable filter with frequency detection. It detects the dominantfrequency and automatically sets a narrow bandpass filter to clean the incoming signal.
If the incoming signal frequency is out of range of the filter bank, a built-in bypass path is selected, therefore
the SHF C981 A is useable up to 65 GHz.
This makes the SHF C981 A an ideal “clock cleaner” e.g., for triggering sampling oscilloscopes.

FeaturesAutomatic filter bank between 2 GHz – 18 GHzFrequency detection between 4 GHz – 60 GHz1



Bypass function from 0.1 GHz up to 65 GHzFilter bandwidth of typ. 1/6 of center frequency with a band stop suppression up to. 50 dB

Useable divided by 2 and divided by 4 outputs for further clock distribution

Accessories
In addition to the module itself, the following parts are complementary and parts of each delivery.
+12 V Power Supply Desktop AdapterHeat-Sink (mounted to the device)Functional Earth CableMini-USB cable

1For frequencies below 4 GHz and above 60 GHz, a manual input within the SHF Control Center GUI is required

SHF reserves the right to change specifications and design without notice
V001 - Feb. 27, 2024 - Page 2

Data Sheet SHF C981 A
SHF Communication Technologies AG

Block Diagram

Ease of UseOnly a single 12 V supply (complementary part of the delivery) is needed for operation.

Upon delivery, the SHF C981 A is ready to use, without any further configuration.

The SHF C981 A can be controlled by intuitive graphical user interface (SHF Control Center) via USB.

SCC GUISHF reserves the right to change specifications and design without notice
V001 - Feb. 27, 2024 - Page 3

Data Sheet SHF C981 A
SHF Communication Technologies AGSpecifications
Absolute Maximum Ratings
Parameter

Unit

SymbolInput Power

dBm

Pin

External DC Voltage on RFPortsV

Vdc

Min

TypMaxComment

10-66

Electrical Characteristics (At 35°C case temperature, unless otherwise specified)Parameter

Unit

Symbol

MinTypMax

Input PowerdBm

Pin-90Useable Frequency Range

GHzf0.165Filter Range

GHzf218

Frequency Detection

GHzf460

Clock /2

GHzf230

See2

Clock /4GHzf115See2

Amplitude Clock /2

mVpp

Ac24001000

See3

Amplitude Clock /4mVpp

Ac46001000

See3

Filter BandwidthMHzfbw

Band Stop RejectiondBc

Signal Gain

dBG

Settling Time

msT

Maximum Gain during
Frequency SwitchingdBGmax

10Psat

dBm

Psat

18

RMS Jitter

fsJrmsSee4

Duty Cycle

%DuCy

See4

Fc/6CommentFc = Center frequency

30-14Up to 50 GHz. For further
information see Page 7202Above 60 GHz and below 4 GHz the divider stages may produce signals with random frequency

3Does not depend on Input Power, decreases with increasing frequency

4No Signal degradation in Jitter or duty Cycle were observed for sin or square wave signals

SHF reserves the right to change specifications and design without notice
V001 - Feb. 27, 2024 - Page 4

Data Sheet SHF C981 A
SHF Communication Technologies AG

Power requirements
Parameter

Unit

SymbolMin

TypMaxConditions

Supply Voltage

VVin11.75

1212.252 mm x 5.9 mm Power Jack

Supply CurrentmA

Iin

1000

Power Dissipation

WPdiss

12UnitSymbolMaxConditions

Mechanical Characteristics
ParameterMinTypInput Connector

1.85 mm (V) female5

Output Connector

1.85 mm (V) female3

Input/2 Connector

2.92 mm (K) female3

Input/4 Connector

2.92 mm (K) female3

Dimensions

mmWeightg

see pages 10 & 11180

W/o Heatsink

480

With Heatsink and Fan

5

Other gender configurations are available on request.
Other connector types, e.g. 2.92 mm (K) or Mini-SMP (GPPO) connectors, are also available but may impact the bandwidth and reflection characteristic.

SHF reserves the right to change specifications and design without notice
V001 - Feb. 27, 2024 - Page 5

Data Sheet SHF C981 A
SHF Communication Technologies AG

Output Filtered Waveform
The measurements below had been performed using a signal generator (Anritsu MG3697C), SHF C991 A(clock distribution) and a DCA (Agilent 86100D) with a Precision Time Base (Agilent 86107A). The output of
the SHF C981 A had been connected directly to the DCA input.

Input Signal @ 3 GHz

Output Signal @ 3 GHz

Input Signal @ 12 GHz

Output Signal @ 12 GHz

Input Signal @ 18 GHz

Output Signal @ 18 GHz

SHF reserves the right to change specifications and design without notice
V001 - Feb. 27, 2024 - Page 6

Data Sheet SHF C981 A
SHF Communication Technologies AG

Typical Bypass Waveform
The measurements below had been performed using a signal generator (Anritsu MG3697C), SHF C991 A(clock distribution) and a DCA (Agilent 86100D) with a Precision Time Base (Agilent 86107A). The output of
the SHF C981 A had been connected directly to the DCA input. The Phase reference was clocked by the /2
Output of SHF C981 A.

Bypass Signal @ 10 GHz

Bypass Signal @ 18 GHz

Bypass Signal @ 35 GHz

Bypass Signal @ 40 GHz

Bypass Signal @ 60 GHz

Bypass Signal @ 65 GHz

SHF reserves the right to change specifications and design without notice
V001 - Feb. 27, 2024 - Page 7

Data Sheet SHF C981 A
SHF Communication Technologies AG

Typical Clock Divider Waveform
The measurements below had been performed using a signal generator (Anritsu MG3697C) and a DCA(Agilent 86100D) with a Precision Time Base (Agilent 86107A). The output of the SHF C981 A had beenconnected directly to the DCA input. The Phase reference was clocked by the /4 Output of SHF C981 A.

Clock /2 @ 4 GHz Input

Clock /4 @ 4 GHz Input

Clock /2 @ 20 GHz Input

Clock /4 @ 20 GHz Input

Clock /2 @ 60 GHz Input

Clock /4 @ 60 GHz Input

SHF reserves the right to change specifications and design without notice
V001 - Feb. 27, 2024 - Page 8

Data Sheet SHF C981 A
SHF Communication Technologies AG

Typical Gain
The following diagram shows the typical input to output gain in normal operation. Between 2 GHz and 18 GHzthe output is filtered.

Typical Gain
1086Gain [dB]420-2010203040506070-4-6-8-10Frequency [GHz]SHF reserves the right to change specifications and design without notice
V001 - Feb. 27, 2024 - Page 9

Data Sheet SHF C981 A
SHF Communication Technologies AGØ2.

2Mechanical Drawing with Heat Sink

acdef

42.7
46.4

b44.2
49.3
52.6

58.5
48.6
356.1

16.1

In

Out

48.6

4

2 - 18 GHz

2Div2SHF C981 A/23Tunable Filter00000

Div4/2101101g71

86

SHF CommunicationTechnologies AGUSBFan+12 V DC +12 V

GND

60.5PortConnector

Designation

a2 mm Banana JackPosPortConnectorbMini-USB

Functional Earth1In1.85mm (V) femalecPower Jack 2.0 x 5.9 mm

2Div22.92mm (K) female

dMini Bushing EMI Filter

Fan+12 V

3Div42.92mm (K) femaleeMini Bushing EMI Filter

Fan Tacho

4Out

1.85mm (V) femalef

1 mm Soldering PinGND

gSliding Switch

ServiceControl Interface
Power

all dimensions in mm

For permanent mounting remove the heat sink from the module. In that case, please ensure that adequatecooling of the module is guaranteed. It is recommended to use thermal paste or a thermal gap pad formounting.

SHF reserves the right to change specifications and design without notice
V001 - Feb. 27, 2024 - Page 10

Data Sheet SHF C981 A
SHF Communication Technologies AG

Mechanical Drawing without Heat Sinkbcdef
7.7
11.4

aØ2.2
43.9
49
52.3

6.4

1In2Div2

Out

13.6

7
2.
Ø

6.4

4x

23.5
13.6

42 - 18 GHz

SHF C981 A/2747165

3

Tunable Filter00000

Div45065/235g
SHF CommunicationTechnologies AG3USB

Fan+12 V DC +12 VGND313.665760PosPortConnector

Port1In1.85mm (V) female

a2 mm Banana Jack

2Div22.92mm (K) femalebMini-USB

3Div42.92mm (K) femalecPower Jack 2.0 x 5.9 mm

Power4Out

1.85mm (V) female

dMini Bushing EMI Filter

Fan+12 VeMini Bushing EMI Filter

Fan Tachof

1 mm Soldering Pin

GND

gSliding Switch

ServiceConnector

Designation
Functional EarthControl Interface

all dimensions in mm

Please ensure that adequate cooling of the module is guaranteed.

SHF reserves the right to change specifications and design without notice
V001 - Feb. 27, 2024 - Page 11

Data Sheet SHF C981 A
SHF Communication Technologies AG

SHF Communication Technologies AG
Wilhelm-von-Siemens-Str. 23 D | 12277 Berlin | Germany+49 30 772 051 0sales@shf-communication.com
www.shf-communication.com

SHF reserves the right to change specifications and design without notice
V001 - Feb. 27, 2024 - Page 12