1 Introduction

In modern electronic warfare (EW), radar characterization, and wireless communication testing, the ability to simulate complex signal environments is critical. Pulsed signals serve as the foundation for radar systems, requiring precise control over timing and spectral purity. This application note explores the generation of narrow-pulse signals with concurrent frequency sweeping, utilizing the high-performance architecture of the HAROGIC SGA-60.

1.1 The Challenge of Narrow Pulse Generation

Generating pulses down to 100 ns requires a signal generator with high-speed internal modulation hardware and a fast-settling time. At such narrow widths, the rise and fall times of the pulse become significant. A VSG must maintain a high on/off ratio (isolation) to ensure that the "off" state does not leak power into the system under test, which could skew sensitive sensitivity measurements.

Furthermore, when the pulse width is 100 ns, the spectral main lobe spans roughly 20 MHz (2/Pulse Width), meaning a wide instantaneous modulation bandwidth is required to represent the signal accurately without distortion.

2 SGA-60: High-Performance Vector Signal Generation

The HAROGIC SGA-60 is a compact vector signal generator that addresses these challenges through its advanced digital architecture. Covering a broad frequency range from 9 kHz to 6 GHz, it provides the versatility required for both legacy low-band systems and modern S-band radar applications.

2.1 Pulse Signal Simulation with Analysis

With its 100 MHz instantaneous bandwidth, the SGA-60 can handle not only simple pulsed continuous waves (CW) but also complex intra-pulse modulation, such as Linear Frequency Modulation (LFM) or "chirps." This bandwidth ensures that the steep edges of a 100 ns pulse are preserved, preventing "rounding" of the pulse shape in the time domain.

2.2 Concurrent Pulse and Frequency Sweep

A unique requirement in modern testing is the Pulse-and-Sweep capability. This involves the instrument modulating the carrier with a pulse train while simultaneously stepping or sweeping the carrier frequency across a defined range (e.g., from 9 kHz to 6 GHz). HAROGIC latest released SGA-60 is capable of output such signal smoothly.

To achieve this, the SGA-60 utilizes a fast-locking synthesizer. As the instrument sweeps, the pulse modulation must remain synchronized with the frequency steps. This is particularly useful for:

Filter Characterization: Testing the transient response of filters across their entire passband.

Electronic Countermeasures (ECM): Simulating frequency-agile radar threats that hop or sweep while maintaining a specific pulse repetition interval (PRI).

3 Conclusion

HAROGIC SG series has the ability to generate a 100 ns pulse while sweeping up to 6 GHz provides engineers with a powerful tool for characterizing wideband components and systems. By leveraging a vector architecture with 100 MHz of bandwidth, users can simulate realistic, agile environments that meet the demanding requirements of today's RF and microwave industries.

4 About HAROGIC

HAROGIC combined compact, robust, high-performance RF hardware with agile, intelligent software to help our customers extend RF boundaries.