SHF Communication Technologies AG
Wilhelm-von-Siemens-Str. 23D • 12277 Berlin • Germany
Phone ++49 30 / 772 05 10 • Fax ++49 30 / 753 10 78
E-Mail: sales@shf.de • Web: http://www.shf.deDatasheet
SHF 46213 D
Optical QAM Transmitter

SHF reserves the right to change specifications and design without notice – SHF 46213D V003 – 14. Nov. 2012

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Description
The SHF 46213 D is an optical QAM transmitter unit. It is a field replaceable plug-in module which needs
to be installed in a mainframe type SHF 10001 A/B or SHF 10000 A/B/C Together with other plug-inmodules from this instruments series, a modular and scalable measurement system can be put together.
In a QAM (Quadrature Amplitude Modulation) transmission system, the data is transmitted in the opticalphase and amplitude change between the symbols. Since one transmitted symbol includes theinformation of n bits the symbol rate is reduced by the factor 1/n. Therefore one advantage of a QAM
transmission system is a high spectral efficiency.
The SHF 46213 D uses a parallel modulator which converts 2 electrical data streams (I and Q) of up to 32
GSymbols/s into 1 optical data stream of up to 32 GSymbols/s.
If the input data streams consist of binary signals, the optical output format will be DQPSK. Multilevel
input data streams will generate the PAM/QAM modulation.
Both electrical data streams modulate the light by a thermally stable Chirp-free Lithium Niobate MachZehnder modulator with a phase difference of /2. Before superposition of the two light streams the Q partgets /2 shifted in order to have four different phase states in the transmitted signal.

The 2 data channels can be switched On and Off independently, thus permitting to generate either DPSKor DQPSK signals.
To detect and to demodulate either the I or the Q channel, the 28 Gbps DPSK optical receiver SHF 47215
A is the ideal instrument. It is possible to switch between the I and the Q channel for eye analysis or BER
measurement of both channels separately.
For a 32 Gbps DQPSK BER measurement the SHF Bit Pattern Generators (SHF 12103 A /SHF 12104 A)
can provide the pre-coded I and Q data streams.
For the RZ modes, an amplified clock signal drives a third modulator. The output from this modulator is atrain of pulses of constant width. For the NRZ-QAM modes, the third modulator is biased to allow lightthrough continuously.
The temperature stable modulators and an automatic bias circuit for both the QAM and pulse carver
modulators ensure high stability of the output signal.

Features
32 GSymbol/s optical data streams
Separate analysis of I and Q channel possible
Quick optimization of optical eye diagram performance by user adjustable modulator bias control
All features are computer controlled via Bert Control Center software
All modulators’ bias conditions controlled automatically
Selectable automatic and manual bias control (ABC circuit)

SHF reserves the right to change specifications and design without notice – SHF 46213D V003 – 14. Nov. 2012

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Functional block diagramuC Control

Data modulator

Pulse modulator

MZ
MZ
MZ
Pulse driver

Linear Data drivers

Delayline

CW Light inModulated
Light out

Clock inA
B
Data inSpecifications – SHF 46213D
Parameter

Unit

Min.

Typ.

Max.

Comment

Optical parameters
Wavelength range

C- and L-band

Insertion loss

dB12

DC Extinction ratio

dB20

Return loss

dB3017connector to connector,
maximum transmission
without modulation

Electrical and electro-optical parameters
Electro-optical bandwidth ofData modulator

GHzSymbol rateRZ-QAM
QAM
Drive amplifier electrical return loss
Data
Clock pulse RZ
Data input level
QAM (linear operation)
QPSK (binary signals, limiting)
Clock input level (for RZgeneration)
Dynamic signal to noise ratio
DPSK-mode, either Data A or B

Gsym/s-3dB optical

25

20
532
32dB-10-10
Vpp

Vpp

0.25
0.9
1.2

0.4
0.5

1215

measured withSHF 47215 A
DPSK-receiver.
@ 28Gbps

SHF reserves the right to change specifications and design without notice – SHF 46213D V003 – 14. Nov. 2012

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Absolute maximum ratings
Parameter

Unit

Min.

Typ.

Max.

Conditions

Optical input power

dBm

16

NRZ data amplifier input powerdBm

4

NRZ data

RZ clock driver input power

dBm

5.5

CW

General specifications
Parameter

1Unit

Min.

Typ.

Weightkg

3.3

Dimensions

mm

59x213x450

Power consumption

W

20.5

Operating temperature°C

10Max.

Conditions
w/o Frontpanel Connectors

35

Electrical data input connectors

male K (2.92mm)

Clock input connector

male K (2.92mm)

Optical connectors

FC/PC

1

Other connectors available on request.

SHF reserves the right to change specifications and design without notice – SHF 46213D V003 – 14. Nov. 2012

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Test Measurements
Typical Measurement results
The following equipment was used in obtaining these results:
31
SHF 12103 A Pattern Generator at 28 Gbps, PRBS 2 -1
SHF 1550DFB Laser source set to 15mW output power @ 1550 nm.
AMPAQ EDFA + bandpass filter
Data input levels: 500 mVAgilent 86100A DCA with 70GHz plugin and precision time base module
D(Q)PSK signals detected with SHF 47215 A 28 Gbps DPSK receiver
only Data A switched ON

only Data B switched ON

S/N: 22

S/N: 24Both Data A and Data B channel switched ON(DQPSK), 28 GSymbols/s:

S/N: 17
RZ-DQPSK

CSRZ-DQPSKS/N: 17

S/N: 17

SHF reserves the right to change specifications and design without notice – SHF 46213D V003 – 14. Nov. 2012

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