Introduction to Mini-Circuits Dual Channel Signal Generators
Mini-Circuits continues to drive innovation by offering high-performance, cost-effective instrumentation for the RF market. A recent example is the family of new RF dual-output RF signal generators (https://www.minicircuits.com/WebStore/RF-Synthesized-Signal-Generators.html#product_detail_one).
These compact RF signal generators offer the flexibility that covers a range of frequencies and power levels. The user-friendly GUI provides easy access to the RF signal generators’ many features. At startup, the GUI allows the operator to select either a USB or LAN interface. Note that the LAN interface also supports Power over Ethernet (POE), especially useful for measurements at a distance.
GUI Interface
Figure 1 – Startup Parameters
Figure 1 shows the GUI initial startup screen. The left-hand side of the screen allows control of one or more RF signal generators. Each can be selected with frequency, RF power, RF On/Off, and other parameters set independently. In the lower-left of the GUI, the “On Power Up” button allows the operator to set default startup conditions or choose different ones.
Figure 2 – Modulation Parameters
Controlling other features of the RF signal generator is just as intuitive. At the top left of Figure 2, there are buttons that allow for frequency/power hopping, frequency/power sweeping, modulations (Pulse, AM, FM, Chirp), and Main control. In addition to the GUI, key parameters, such as frequency and power, are displayed on the unit’s front panel.
Another useful feature is that the two RF outputs are phase coherent. This feature, highlighted in Figure 2, is controlled by a button in the lower-left corner of the GUI panel. It is useful for phase-sensitive applications such as phased array antenna test or transmit/receive module test.
The intuitive GUI, combined with flexible hardware, offers the user a variety of measurement options. One measurement that comes quickly to mind is the two-tone, a.k.a. the IP3 or third-order test. With a small footprint, this can be easily accomplished using a single dual RF signal generator to generate the two tones for the measurement. The output of the DUT contains the two original (input) tones plus tones created by internal distortion, as shown in Figure 3.
Other Features
Figure 3 – General representation of harmonics and intermodulation products in the frequency domain.
Other features of the dual RF signal generator can be leveraged as well. For instance, the response of a wireless system to handle interfering signals at different frequencies, power levels, and modulation types. This can be illustrated using Figure 4 as a baseline. Figure 4 is an actual OFDM (Orthogonal Frequency Division Multiplex) signal. Note the characteristic null at the center of the band. It is created at the center bin to prevent local oscillator (LO) leakage and DC offsets from corrupting the transmitted signal. So perhaps we want to understand the behavior of this system in the presence of interfering signal(s).
Figure 4 – A typical OFDM signal.
Figure 5 shows the same OFDM signal, this time with two interfering signals in the band. The first interfering signal is an FM signal centered over the null, and the second is a strong CW signal located 5 MHz above the null.
Across a broad range of test and measurements, the new Mini-Circuits family of RF dual-channel signal generators offer powerful and intuitive capabilities. From phase-coherent test applications to pulsed and modulated scenarios, these RG signal generators are equipped to handle a range of requirements.
Figure 5 – Two interfering signals in an OFDM channel.
Having the capability and flexibility of two phase-coherent RF signal generators in a single package enables a variety of “what if” scenarios to assess the robustness of the unit under test. And similar configurations could be performed for other applications such as chirped signals for radar or pulsed signals for time-division multiplexed signals.
Find out more information at https://www.minicircuits.com/WebStore/RF-Synthesized-Signal-Generators.html#product_detail_one.
Get in touch for orders or any queries: sales@rfdesign.co.za / +27 21 555 8400
Courtesy of Mini-Circuits
