RF Expansion Modules For SF1000 Portable Signal Generator

The new 2500Mand 1800M Frequency Expansion Modules attach to the Signal Forge 1000 Signal Generator,
providing an RF output up to 2.6 GHz. The 2500M features an RF output with a frequency range of 1.5 GHz
to 2.6 GHz programmable in 1 Hz increments. And the 1800M provides an RF output with a frequency range
of 950 MHz to 1.8 GHz. The modules are connected to and controlled by the Signal Forge signal generators.

Applications of Signal Generators

3-in-1 Signal Generator
The Signal Forge 800/1000 Digitally Synthesized Signal Generator combines the features of both a signal source, signal generator and function generator in a single, low-cost device. In addition, the SF800/1000 incorporates features which make it ideal for testing differential systems, such as high speed serial busses, analog and digital circuits, and RF and telecommunication equipment.

Compensating for External Signal Loss
In any RF or analog test setup, there is likely to be signal loss due to cables, attenuators, filters or switches between your source, the Signal Forge 1000 or 800, and the device under test (DUT). The accuracy of the signal level that arrives at the DUT is affected by the sum of these components. This application note describes how to measure the signal loss and how to compensate for for it using the embedded Wave Manager software.

Controlling The SF1000 With An External Program
In some cases it is necessary to control the Signal Forge 1000 (SF1000) programmatically using an external application or controller. This document describes how to create and use an external control file to operate the SF1000.

Controlling The SF1000 Externally - Sample File
This sample file may be used as a guide in developing a program to control the SF1000 externally. See the "Controlling the SF1000 With An External Program" form more information.

Converting LVPECL to LVDS and CML
The Signal Forge Digitally Synthesized Signal Generator provides a differential clock output that conforms to the LVPECL standard. While LVPEC is a widely used standard, there are other differential signaling standards in use today including LVDS and CML. This application note addresses how to interface the LVPECL differential output of the SF800/1000 to conform to the LVDS and CML standards.

External Clock Requirements for the "E" Model
The SF800E/1000E are designed to operate only when and an external 10 MHz digital clock source is attached. (For applications where an external clock source is not available, the SF800/1000 should be used.)

This document defines the requirements for the external 10 MHz reference clock source.

Generating Spectrally Clean Output
The SF800 and SF1000 Signal Generators provides an AC coupled output that can source a sinusoidal output in the range of 100 KHz to 1 GHz. This output provides a signal with harmonics at least 20 dB down (from 300 MHz to 1 GHz) at programmable output power levels. If a cleaner sinewave signal is needed, for example to drive the LO, or a receiver mixer, an external filter may be attached as described in this application note.

I & Q Output
While the Signal Forge 800/1000 does not produce I & Q outputs directly, an external splitter may be used to derive the in-phase and quadrature components from the AC-coupled output. This application note describes how to design an external I & Q splitter.

Increasing or Decreasing the Signal Generator's Output Power
The Signal Forge 800/1000 provides an AC coupled frequency source output with a range of –11 dBm to +7 dBm. By adding an external amplifier or an attenuator to increase or decrease power respectively, the amplitude range may be extended.

Power Conversion Table
This application note provides a conversion between dBm, mW and mV for the entire power range of the Signal Forge 1000.

Signal Generators as Alternative to BER Testers
The traditional method of design margin testing in serial data communication systems is to employ a specially designed bit error rate (BER) tester. While BER testers have proven effective, they are typically expensive and they do not always exercise the system under test with the same level of noise or using the same data patterns that will be seen by the system in the field. This article discusses a test methodology, using signal generators, that may be applied to a wide range of data communication systems and devices which transmit data over a serial bus. This test methodology may be part of the design verification process or it may be used to qualify substitute components after the product has been released to production. In this case, the signal generators uncovered a latent design flaw that had not been detected using a BER tester.


Software Update Procedure
The embedded operating software of the Signal Forge 1000 and 800 Signal Generators may be updated in the field by following the procedure described in this document. Any available software updates may be on the Support page of the Signal Forge web site www.signalforge.com.

Testing Amplifiers with the Signal Forge Portable Signal Generator
This application note describes a low-cost way to test amplifiers for gain as well as for the 1dB compression point.

Testing Digital Systems
The Signal Forge 1000 / 800 may be used to test the design margins of a digital system by varying the clock input to the system from min to max. This test ensures that the design maintains the required setup and hold times under all conditions.

Testing High-Speed Serial Busses
Proper operation of high-speed serial busses requires that data integrity be maintained between the two devices under test (eg. a disk controller and a disk drive) even though these devices are not being driven from the same clock source. Since operation and compatibility must be guaranteed across a range of frequency variations and manufacturing variances, it is imperative to test many device samples under varying conditions. This application note discusses how to configure a test serial bus devices using the Signal Forge 1000 or Signal Forge 800.

Testing IP3 with the Signal Forge 1000 and 800
This application note describes how to build a low-cost IP3 tester for amplifiers.

Testing Wireless Data Transmission Systems
Amplitude Shift Keying (ASK) and On/Off Keying (OOK) are two techniques used to test and exercise digital data transmission systems such as wireless security systems, keyless entry systems and garage door openers. This application note describes how to use the ASK and OOK waveform modulation functions of the Signal Forge 1000 Signal Generator for testing wireless digital data transmission systems.

USB to Serial Adapter
Keyspan's USB - Serial adapter makes the Signal Forge 1000 or Signal Forge 800 Signal Generator accessible from a USB port.

All Signal Generators Feature

Small, portable package
RF output 1 KHz to 1 GHz (SF1000 supports 2.6 GHz with add-on modules)
Digital output 1 Hz to 110 MHz
Differential output 50 MHz to 1 GHz
Modulation functions include: AM, ASK, BPSK, Chirp, FM, FSK, OOK,
Sweep Signal Generator