NIPXI-2546

400 MS/s, 16-Bit I/Q Signal Generator NI PXIe-5450 NEW! • Dual-channel, differential I/Q signal generation • 16-bit resolution, 400 MS/s sampling rate per channel • 98 dB close-in SFDR at 1 MHz • 145 MHz analog bandwidth for generating 290 MHz bandwidth RF signals • ±0.15 dB flatness to 120 MHz with digital flatness correction • 25 ps channel-to-channel skew • 600 MB/s from host • 1 Vpk-pk output, 2 PXI slots Operating Systems • Windows Vista/XP/2000 Recommended Software • • • • • • • • • • LabVIEW LabWindows™/CVI LabVIEW SignalExpress Measurement Studio NI-FGEN driver NI-FGEN Express VIs NI Modulation Toolkit NI Analog Waveform Editor FGEN Soft Front Panel LabVIEW Real-Time driver Included Software Calibration • Self-calibration with gain and channel alignment; offset correction • 1-year external calibration cycle Overview The NI PXIe-5450 is a 16-bit, 400 MS/s, dual-channel arbitrary waveform generator optimized for I/Q communications signals. Each of the differential outputs features 98 dB of close-in spurious-free dynamic range (SFDR) at 1 MHz (without harmonics), better than -140 dBc/Hz phase noise density at 10 MHz (1 kHz offset), and less than 25 ps channel-to-channel skew. The NI PXIe-5450 is the ideal instrument to test devices with I/Q inputs or to serve as the baseband component of an RF vector signal generator. It also features onboard signal processing (OSP) functions that include pulse shaping and interpolation filters, gain and offset control, and a numerically controlled oscillator (NCO) for frequency shifting. Common applications include prototyping, validating, and testing of semiconductor components and communications, radar, and electronic warfare systems. With its NI Synchronization and Memory Core (SMC) architecture, the NI PXIe-5450 helps you integrate mixed-signal test systems by enabling synchronization with other instruments such as vector signal analyzers/ generators, high-speed digitizers, digital waveform analyzers/generators, and other signal generators. You can also synchronize multiple arbitrary waveform generators to form a phase-coherent multichannel generator for applications such as MIMO (multiple-input, multiple-output) or beamforming antenna schemes. Signal Quality With 16 bits of resolution, the NI PXIe-5450 achieves a close-in SFDR (without harmonics) of 98 dB at 1 MHz. Including harmonics and measured from DC to 200 MHz, it achieves a 1 MHz SFDR of 75 dB and a wideband SFDR of 70 dB at 60 MHz. This ensures the dynamic range and out-of-band performance needed to meet the stringent demands of baseband I/Q signal generation (Figure 1). Figure 1. With its high sample rate and resolution, the NI PXIe-5450 generates low-distortion, high-SFDR signals over a very high bandwidth (the noise floor is limited by the measurement device). 400 MS/s, 16-Bit I/Q Signal Generator The NI PXIe-5450 also delivers exceptional passband flatness (Figure 2). While the -3 dB analog bandwidth is 145 MHz, the digital flatness correction filter provides ±0.15 dB of flatness from DC to 120 MHz. 1– 0.5 – 0– –0.5 – –1 – –1.5 – Amplitude (dB) –2 – –2.5 – –3 – –3.5 – –4 – –4.5 – –5 – –5.5 – –6 – 0 Flatness Correction Enabled Flatness Correction Disabled 20 40 60 80 100 Frequency (MHz) 120 140 160 180 Figure 3. Dedicated channel-alignment circuitry automatically calibrates the two channels on the NI PXIe-5450 to within 25 ps. This particular module exhibits less than 13 ps of skew, demonstrated on a 100 MHz sinusoid. – – – – – – – – – – – – – – – – – – – – Figure 2. Passband flatness is significantly improved with the use of digital flatness correction in the NI PXIe-5450 FPGA. High-Speed Data Streaming In addition to tight synchronization, the SMC architecture on the NI PXIe-5450 takes advantage of the PCI Express bus to continuously stream data from the host controller at more than 600 MB/s in dual-channel mode or at 360 MB/s when generating a single channel. This enables the module to continuously output I/Q waveforms at 150 MS/s or, when upconverted, approximately 120 MHz RF bandwidth, either from host memory or a high-speed storage solution such as the NI HDD-8264 3 TB RAID array. With this technology, you can generate terabyte waveforms of unique, high-bandwidth data for several hours. Applications that benefit from this capability include RF and baseband recording and playback for signal intelligence and communications system design, validation, and verification. For maximum signal purity, the phase noise of this module is extremely low. The phase noise density of a tone generated at 10 MHz drops from -121 dBc/Hz at a 100 Hz offset to -150 dBc/Hz at 100 kHz, yielding an integrated system output jitter of less than 500 fs. Its highly stable phase-locked loop (PLL) and high-resolution oscillator provide an output sample rate resolution less than 5.7 µHz, enabling low phase noise signal generation at any frequency with microhertz resolution. An essential attribute for I/Q generation is tight synchronization between channels. The NI PXIe-5450 features high-performance circuitry that calibrates the channel skew to within 25 ps. You can achieve even more alignment with a 10 ps resolution programmable skew, useful in calibrating out cable length mismatches. This tight level of synchronization minimizes the phase error between channels, especially at high frequencies, which is essential for accurately generating highbandwidth I/Q signals (Figure 3). Onboard Signal Processing OSP significantly extends waveform playback time and shortens waveform download times (Figure 4). A field-programmable gate array (FPGA) on the NI PXIe-5450 implements the OSP functionality, which enables several signal processing and I/Q-related functions. These functions include those listed on page 3. Onboard Signal Processing Pre-Filter Gain I I/Q Rate Pre-Filter Gain Q Pre-Filter Offset I Pre-Filter Offset Q Filtering and Interpolation I Filtering and Interpolation Q Digital Gain I Digital Gain Q DAC I Waveform Memory Output Engine Frequency Shift by NCO DAC Q Figure 4. OSP on the NI PXIe-5450 FPGA performs inline processing of waveform data before it is sent to the digital-to-analog converter (DAC) . BUY ONLINE a t ni.com o r CALL 800 813 3693 (U.S.) 2 400 MS/s, 16-Bit I/Q Signal Generator • Independent I and Q prefilter gain and offset – Adds gain and offset imbalance impairments and I and Q prefilter gain. You can adjust the offset before or during the generation of an output signal (Figures 5, 6). • Baseband interpolation – Generates smooth baseband signals. You can use the NI PXIe-5450 OSP block to interpolate low-sample rate waveforms to a much higher sample rate, thereby improving the output frequency spectrum by relocating zero-order sample-and-hold reconstruction images to higher frequencies. With the images at higher frequencies, the device’s image suppression filter greatly suppresses them without disturbing the signal’s amplitude response or phase information. Waveform Sequencing and Triggering You also can program the NI PXIe-5450 to sequence and loop a set of waveforms. You can choose from several methods to step through the sequence of waveforms. In cases when you know the duration of each waveform in advance, you can program the generator to loop them a specified number of times. When you do not know the duration before the start of generation, you can use a hardware or software trigger to advance the generator to the next waveform in the sequence. The NI PXIe-5450 implements advanced triggering behavior with four trigger modes: single, continuous, burst, and stepped. In addition, scripting provides the ability to link and loop multiple waveforms together, managing triggers and markers. For a detailed discussion of these modes, consult the NI Signal Generators Help guide available at ni.com/manuals. NI SMC-based generators have the unique capability of storing multiple sequences and their associated waveforms in the generator’s onboard memory (see Figure 7). In automated test applications involving multiple tests, each requiring a different waveform sequence, you can download all of the sequences and waveforms once at the beginning of the test cycle and store them in the generator’s memory for the entire session. By downloading all required waveforms and sequences once to an SMC-based generator instead of repeatedly reloading them for each test, you save time and improve throughput. Waveform 1 Waveform 2 ••• Waveform n Sequence Instructions 1 Sequence Instructions 2 ••• Sequence Instructions m Free Memory Figure 5. LO leakage and poor image rejection of a quadrature modulator cause undesired RF emissions. Figure 7. NI SMC-based arbitrary waveform generators increase test throughput by storing all the waveforms and sequences required for a set of tests in onboard memory. Figure 6. On-the-fly-adjustable parameters on the NI PXIe-5450 correct for the quadrature modulator impairments seen in Figure 5. Timing and Synchronization Using NI T-Clock (TClk) synchronization technology, you can synchronize multiple NI PXIe-5450 modules for applications requiring a greater number of channels, such as I/Q signal generation for MIMO systems. Because it is built into the SMC, TClk can synchronize the NI PXIe-5450 with SMC-based vector signal analyzers and generators, high-speed digitizers, and digital waveform generators and analyzers for tight correlation of analog and digital stimulus and response. Using onboard calibration measurements and compensation, TClk can automatically • Pulse-shaping finite impulse response (FIR) filter – Shapes and interpolates the waveform data. FIR filter types include flat, raised cosine, and root raised cosine, with a programmable α parameter. Digital interpolation factors range from 2 to 32,768 times. • Numerically controlled oscillator (NCO) – Produces sinusoidal waveform data for complex (I/Q) frequency shifts before or during generation with up to a ±86 MHz shift and 710 nHz resolution. NCO tuning time is 250 µs. BUY ONLINE a t ni.com o r CALL 800 813 3693 (U.S.) 3 400 MS/s, 16-Bit I/Q Signal Generator synchronize any combination of SMC-based modules with less than 500 ps module-to-module skew. Greatly improved from traditional synchronization methods, the skew between modules does not increase as the number of modules increases. To achieve even better performance, you can use a high-bandwidth oscilloscope to precisely measure the module-to-module skew. With the oscilloscope measurement for calibration information, TClk can achieve