SHF Communication Technologies AG
Wilhelm-von-Siemens-Str. 23D • 12277 Berlin • Germany
Phone +49 30 772 051-0 • Fax +49 30 753 10 78
E-Mail: sales@shf-communication.com • Web: www.shf-communication.com

Datasheet
SHF S126 ABroadband Amplifier

SHF reserves the right to change specifications and design without notice - SHF S126 A - V002 - Oct. 24, 2019

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Description
The SHF S126 A broadband amplifier is the RoHS compliant successor of the popular SHF 826H. By
applying new packaging techniques, this amplifier keeps the RF parameters, such as bandwidth andoutput power, at the same high level as the predecessor while enhancing the gain and the signal quality.
Data rates up to 32 Gbps with output amplitudes of up to 12 V are possible.
The S126 A is a two-stage amplifier design, using proprietary monolithic microwave integrated circuits(MMICs) inside. An internal voltage regulation protects the amplifier against accidental reverse voltage
connection and makes it robust against line voltage ripple.

Ease of Use
Upon delivery, the amplifier is already pre-set to deliver maximum gain, maximum output amplitude andnominally 50% crossing.
These settings can be modified in an easy to use graphical user interface, as shown below. For
connecting the amplifier to the computer, the USB to I2C converter cable, as well as the required
software are included with each amplifier with no extra charge.
Once new settings are stored on the device the amplifier will remember the settings until further
changes are made. There is no need to connect a computer to the device unless gain, maximum
amplitude or crossing adjustments are to be made.
The software is available for download at www.shf-communication.com .

GUI of the SHF amplifier control software

Available Options
01: DC return on input (max. ±1.75 V, max. 35 mA)

1

02: Built-in bias tee on input (max. ±9 V, max. 220 mA)
03: DC return on output (max. ±1.75 V, max. 35 mA)

1

1

04: Built-in bias tee on output (max. ±9 V, max. 220 mA)

1

MP: Matches the phase of two amplifiers

1The options 01 & 02 or 03 & 04 cannot be combined.
If an option is chosen, the maximum gain and the maximum output power might be reduced by up to 1 dB. The low frequency 3 dB Point might beincreased up to 100 kHz. The DC resistance of an bias tee is about 3 Ω.

SHF reserves the right to change specifications and design without notice - SHF S126 A - V002 - Oct. 24, 2019

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Specifications – SHF S126 AParameter

Unit

SymbolMin

TypMax

Conditions

Maximum RF Input Powerin OperationdBm
V

Pin max

41

peak to peak voltage

Maximum RF Input Powerwithout Power Supply

dBm
VPin max

102peak to peak voltage

DC Voltage at RF Input

V±9DC Voltage at RF Output

V±9Supply Voltage

VAbsolute Maximum Ratings

Case Temperature

2Tcase11°C

1013450.6 A, reverse voltage protected

50Electrical Characteristics (At 45°C case temperature, unless otherwise specified)

2High Frequency 3 dB Point

GHzfHIGH

25Low Frequency 3 dB PointkHz

fLOWGaindB

S21Max. Gain ReductiondB

Output Power at 1 dB
Compression

dBm
V

P01dB

23
8.9

50 MHz…15 GHz

Output Power at 2 dB
Compression

dBm
V

P02dB

24
1050 MHz…15GHz

Output Power at 3 dB
CompressiondBm
VP03dB25
11.2

50 MHz…15 GHz

Crossing Control
Range%

Input Reflection

dBS11-8< 25 GHz

Output Reflection

dBS22-10-5< 13 GHz

802829-2.5-30

non-inverting
measured at Pin=-27 dBm-4Control via software interface

peak to peak voltage

peak to peak voltage

peak to peak voltage

10Control via software interface@ 450 mV input signal amplitude< 20 GHz

If operated with heat sink (part of the delivery) at room temperature there is no need for additional cooling.

SHF reserves the right to change specifications and design without notice - SHF S126 A - V002 - Oct. 24, 2019

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ParameterUnit

SymbolMin

TypMaxConditions
20%...80%, 11 V ≤ Vout ≤ 12 V

Rise Time/Fall Time

pstr/tf

1317

Deconvoluted
Full Setup

3, 4

3Vout ~12 V, 32 Gbps

Jitterfs

Group Delay Ripple

psPower Consumption

W

JRMS

700
750

6.2

3, 4850900

Deconvoluted±50

1 GHz…15 GHz, 160 MHz aperture

Full Setup

312 V supply voltage

Mechanical Characteristics
5

Input Connector

2.92 mm (K) female

Output Connector

2.92 mm (K) male

5Output Amplitude Adjustment
The Output Amplitude can be adjusted by the GUI. The maximum possible reduction depends on theoutput amplitude itself, i.e. a minimum input power of -3 dBm is required to achieve a output power
reduction of at least 4 dB. Lower output power levels will result in an reduced output power reduction range.
By using the Amplitude Adjustment it is required to adjust the crossing too.

34Measured with the following setup: SHF 12103A BPG -> DUT (SHF S126 A) -> Agilent 86100A with 70 GHz sampling head and precision time base.
Calculation based on typical results of setup without DUT :𝑡𝑟 /𝑡𝑓 𝑑𝑒𝑐𝑜𝑛𝑣𝑜𝑙𝑢𝑡𝑒𝑑 = √(𝑡𝑟 /𝑡𝑓 𝑓𝑢𝑙𝑙 𝑠𝑒𝑡𝑢𝑝 )2 − (𝑡𝑟 /𝑡𝑓 𝑠𝑒𝑡𝑢𝑝 𝑤/𝑜 𝐷𝑈𝑇 )2 = √(𝑡𝑟 /𝑡𝑓 𝑓𝑢𝑙𝑙 𝑠𝑒𝑡𝑢𝑝 )2 − 11 𝑝𝑠 2
2𝐽𝑅𝑀𝑆 𝑑𝑒𝑐𝑜𝑛𝑣𝑜𝑙𝑢𝑡𝑒𝑑 = √(𝐽𝑅𝑀𝑆 𝑓𝑢𝑙𝑙 𝑠𝑒𝑡𝑢𝑝 )2 − (𝐽𝑅𝑀𝑆 𝑠𝑒𝑡𝑢𝑝 𝑤/𝑜 𝐷𝑈𝑇 ) = √(𝐽𝑅𝑀𝑆 𝑓𝑢𝑙𝑙 𝑠𝑒𝑡𝑢𝑝 )2 − 300 𝑓𝑠 2
5

Other gender configurations are available on request.
Other connector types, e.g. 1.85mm (V) 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 - SHF S126 A - V002 - Oct. 24, 2019

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Typical S-Parameters, Group Delay and Phase Response

Aperture of group delay measurement: 160 MHz

SHF reserves the right to change specifications and design without notice - SHF S126 A - V002 - Oct. 24, 2019

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Typical Noise Figure
The measurement had been performed using a FSW85 Spectrum Analyzer by Rhode & Schwarz. The
noise figure defines the degradation of the signal-to-noise ratio when the signal passes the amplifier. An
ideal amplifier would amplify the noise at its input along with the signal. However, a real amplifier adds
some extra noise from its own components and degrades the signal-to-noise ratio. Please note that thisapplies to small signals only. When the amplifier is used close to or in its saturation region additional
non-linear effects will impact the signal-to-noise ratio and the signal waveform.

1098Noise Figure [dB]

765
43
2
1005

10

15

20

25

30

Frequency [GHz]SHF reserves the right to change specifications and design without notice - SHF S126 A - V002 - Oct. 24, 2019

Page 6/12Typical Binary Waveforms
Measurements had been performed using a SHF 12103 A BPG and an Agilent 86100C DCA with Precision
Time Base Module (86107A) and 70 GHz Sampling Head (86118A).

Eye Amplitude: Input ~480 mV ⇒ Output ~12 V

Input Signal @ 10 Gbps

Output Signal @ 10 Gbps

Input Signal @ 20 Gbps

Output Signal @ 20 Gbps

Input Signal @ 32 Gbps

Output Signal @ 32 Gbps

SHF reserves the right to change specifications and design without notice - SHF S126 A - V002 - Oct. 24, 2019

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Typical 4-Level Waveforms
Measurements had been performed using a SHF 611 C DAC with low pass filter 17 GHz and an Agilent
86100C DCA with Precision Time Base Module (86107A) and 70 GHz Sampling Head (86118A).

Eye Amplitude: Input ~340 mV ⇒ Output ~10 V

Input Signal @ 10 GBaud

Output Signal @ 10 GBaud

SHF reserves the right to change specifications and design without notice - SHF S126 A - V002 - Oct. 24, 2019

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Typical Low Frequency Response (<40 MHz)

Typical Saturation power

Top (red): 3 dB compression;
Middle (green): 2 dB compression;
Bottom (blue): 1 dB compression

SHF reserves the right to change specifications and design without notice - SHF S126 A - V002 - Oct. 24, 2019

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M4x5mm

19Mechanical Drawing with Heat Sink

55

15.4
15135

15

15.4

10.1
15.2
26.2

nc

7.8
I2C
GND +12V
0.6A

nc

2.5

4.5

16
29.5

150

50

19.8
15.4
15

39.5
29.5
16

all dimensions in mm

Pin assignment might change if a bias tee option is chosen.
For permanent mounting remove the heat sink from the amplifier. In that case please ensure thatadequate cooling of the amplifier is guaranteed. It is recommended to use thermal paste or a thermal
gap pad for the mounting. In order to separate the heat sink from the amplifier, remove the four screws
on the heat sink. Please note, thermal paste is used between the heat sink and the amplifier housing.

SHF reserves the right to change specifications and design without notice - SHF S126 A - V002 - Oct. 24, 2019

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Mechanical Drawing without Heat Sink

23.6

4x M2x 5 mm

9.8

55.4

211023.5
35M2 x5mm

42+1-0512.8

275.1

39.7

9.8

21.29.632

10.2

27.9

ncnc

54

GND +12V
0.6A

37.3

226I2C

6140

5.4

23.5

55.4

10

all dimensions in mmPos.
1234567Connector
Input
Outputnc (optional)
GND+12 V / 0.6 A
2ICnc (optional)

Pin assignment might change if a bias tee option is chosen.
Please ensure that adequate cooling of the amplifier is guaranteed.

SHF reserves the right to change specifications and design without notice - SHF S126 A - V002 - Oct. 24, 2019

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User Instructions
ATTENTION!
Electrostatic sensitive GaAs FET amplifier1.

To prevent damage through static charge build up, cables should be always discharged before
connecting them to the amplifier!

2.

Attach a 50 Ohm output load before supplying DC power to the amplifier!

3.

The supply voltage can be taken from any regular 11 …13 V, (0.6 A @ 12 V) DC power supply andcan be connected to the supply feed-through filter via an ON / OFF switch.
In case 12 V are applied to the amplifier typically 0.5 A are drawn during operation. However, theamplifier requires more current during start up. This is particularly important in case the current
compliance of a very fast acting voltage source is set too tight. As this can prevent the amplifier fromstarting properly, please allow up to 100% overhead for your current compliance during startup.

4.

Using a 3 dB or 6 dB input attenuator will result in a 6 dB or 12 dB increase of the input return loss.
For minimal degradation of amplifier rise time, these attenuators should have a bandwidth
specification of greater 30 GHz (K / 2.92 mm attenuators)!

5.

A input signal of about 0.55 Vpp will produce output swing of about 12 Vpp. Higher input voltages areleading to waveform degradation.

6.

The amplifier can only be used without damage by connecting a 50 Ohm precision load to the output.

7.

ATTENTION: At radio frequencies a capacitive load can be transformed to an inductive one throughtransmission lines! With an output stage driven into saturation this may lead to the immediate
destruction of the amplifier (within a few ps)!

8.

The input voltage should never be greater than 1 Vpp equivalent to 4 dBm input power.

9.

For the DC-connections flexible cable 0.2…0.5 mm / AWG 24…20 are recommended. A maximum
soldering temperature of 260 °C for 3 seconds is recommended for the feedthrough (positive supply
voltage and bias tee pin). The ground pin requires significantly more heat as it is connected to thesolid housing.

2

SHF reserves the right to change specifications and design without notice - SHF S126 A - V002 - Oct. 24, 2019

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