8 Virtual Signal Generators on the M9484C

The M9484C VXG signal generator by Keysight Technologies offers an extensive frequency range from 9 kHz to 54 GHz, wide bandwidths, and supports multichannel applications. It sets industry benchmarks in capability, scalability, and performance. The instrument’s advanced technology includes the unique ability to emulate 8 virtual signals simultaneously in real-time from a single RF source. Depending on the system configuration, the instrument can emulate as many as 32 signals, with each RF output supporting 8 virtual signals. This capacity can be further expanded with the synchronization of multiple M9484C instruments, allowing for flexible and scalable operation in complex testing environments.

The M9484C incorporates many advanced technologies that enable real-time emulation of up to 8 simultaneous signals from a single RF source. A key performance component is the use of Direct Digital Synthesis (DDS) generators. DDS generators eliminate the need for an I/Q modulator, which enhances performance significantly compared to traditional baseband generators. This advanced technology results in cleaner performance, eliminating the distortion associated with I/Q modulator images, Local Oscillator (LO) feedthrough, and I/Q modulator instability. The DDS architecture is further illustrated through multiple block diagrams included in the application note.

Leveraging these advanced technologies, the M9484C can emulate up to 8 virtual signals per RF channel simultaneously in real-time. To better understand this capability, a demonstration of 8 virtual simultaneous signals is included in the application note, along with descriptions of the per-signal features, key operating parameters, and notable features. The demonstration includes captured images of signal generation at the instrument interface, as well as the resulting signal captured on a Keysight Signal Analyzer. The per-signal features include state, frequency, power, signal mute and attenuation, phase, trigger delay, and signal modulation capabilities. To summarize each per-signal feature, a table is included in the application note listing their presentation format (absolute or relative) and their disruptive or non-disruptive nature.

The M9484C operates within several key parameters that impact the performance of the 8 virtual signal generators. These parameters include sample rate, maximum baseband flat bandwidth, RF output power, and waveform creation. The instrument utilizes a shared sample rate of 3 GSa/s, which can be split among the virtual signals provided it does not exceed that limit. The maximum baseband flat bandwidth is dependent on the unit’s configuration, with Option R25 offering the greatest RF bandwidth of 2.5 GHz. Additional details regarding RF output power and waveform creation are found in the application note.

With the M9484C’s advanced technology and operating parameters, the instrument’s dynamic range performance is 20-40 dB better than that of traditional signal generators. Testing capabilities can be further expanded with global triggering across RF channels or across instruments. Each instrument has the potential to support up to 32 virtual signals, with 8 signals per RF channel, and this capacity increases when using multiple M9484C signal generators together. This scalability supports a wide range of complex, high-density testing applications.

The combination of the M9484C’s advanced technology, operating parameters, and system features enables the use of 8 virtual signal generators across a wide range of testing scenarios, significantly improving efficiency and ease-of-use. These scenarios include, but are not limited to, MIMO, interference analysis, carrier aggregation, and Electromagnetic Spectrum Operations (EMSO). A brief explanation and a simple example are given for each testing scenario in the application note. The 8 virtual signal capability is relevant across sectors ranging from cellular networks to aerospace defense and general communications. It further supports a broad range of applications beyond those highlighted.

The M9484C VXG by Keysight Technologies establishes a high-performance standard through its extensive frequency range, wide bandwidths, support for multichannel applications, and 8 virtual signal generation capability. It enables real-time emulation of up to 8 signals simultaneously per RF channel using a single source. The Keysight M9484C VXG’s advanced technologies, operation, and features make it an indispensable instrument for achieving greater efficiency, accuracy, and confidence in even the most demanding RF test applications.