In this episode Shahriar performs a full review on the Tektronix MDO4000C series mixed domain oscilloscope, particularly model MDO4104C-6. The MDO4000C combines up to six instruments including a function generator and a built-in spectrum analyzer. Unlike any other instrument, it can synchronize RF, analog and digital channels. These correlated measurements provide insight into difficult to find problems particularly intermittent events.
This review begins with a comparison between the MDO4000B and MDO4000C instruments. The full review of the MDO4000B can be viewed here. All experiments demonstrated in the MDO4000B review are also relevant to the MDO4000C instrument.
The teardown of the instrument reveals a multi-board construction where the ADCs, FPGAs, application processor and memory are on the main system board. A complete analysis of the entire system is presented including the operation of the RF module.
In order to demonstrate the instrument’s capabilities, an encrypted frequency hopping transmitter system is analyzed. The system exhibits various problems such as high BER, low SFDR, poor phase-noise and EVM. The MDO4000C is used to perform advanced measurements across analog, digital and RF domain to track and resolve these problem. The complete block diagram of the experiment can be found here.
Low noise: 1:1 attenuation ratio probe adds only 10% to the baseline noise of the oscilloscope it is attached to.
Large offset range: Has a large +/-24 V offset range, enabling users to set their oscilloscope at maximum sensitivity and have the signal centered on the screen.
Low DC loading: 50 kΩ DC input impedance will not significantly load DC power rails.
Large active signal range: Has a +/-850 mV active signal range in addition to its large offset range so users can measure large transitions of their power rails.
High bandwidth: 2-GHz bandwidth makes it very useful for finding high-speed transients that can have detrimental effects on clocks and digital data.
After a brief presentation about the benefits of the N7020A, the probe and probe accessories are examined. The probe’s capability to provide up to +/-24V of offset is demonstrated and the input impedance at DC is measured. The probe is then used in conjunction with a Xilinx FPGA board to characterize a broadband power supply noise issue.
In this episode Shahriar presents a detailed review of the new Tektronix TSG4106A RF Signal / Vector Generator. The key features are:
True DC to 2 GHz, 4 GHz or 6 GHz to support both analog and vector/digital signal generation.
Typical ≤±0.30 dB amplitude accuracy (0 dBm CW signal at 22 ºC) from 10 MHz to 6 GHz.
I/Q modulation inputs (400 MHz RF bandwidth).
ASK, FSK, MSK, PSK, QAM, VSB, and custom I/Q.
A complete teardown of the unit is presented along with an explanation of various functions, components and sub-systems. The basic unit performance is verified using a Keysight EXA Signal Analyzer. The TSG4106A is then used to along with an Analog Devices I/Q de-modulator whose output is examined for performance verification.
The full instrument block diagram is presented with focus on various signal paths and frequency planning. Several of internal modules (RF Front-End, Digital Baseband Processor and LO Synthesizer) are also presented and compared with the block diagram. In order to examine the instrument’s capabilities in a real-world situation, a complete superheterodyne wireless transceiver with a sliding-IF receiver is designed and examined. Each component in the system (LNA, mixer, PLL, etc.) is individually characterized by using the EXA Signal Analyzer. The complete system measurements are also presented.
Various chapters in the video can be found at the following time marks:
X-Series model comparison (0:50)
EXA block diagrams and principle of operation (4:27)
Various board teardown and examination (20:39)
Instrument front/back panel overview (37:05)
Wireless experiment setup description (43:22)
Doubler characterization with EXG as the tracking generator (45:31)
LNA and mixer gain and NF by using Noise Figure personality (57:31)
Signal-Hound VSG25A I/Q modulator characterization, OBW, ACPR, TOI (1:08:57)
PLL characterization with Phase Noise personality (1:19:49)
Full transmitter measurement with Keysight VSA (1:26:08)
Full wireless link characterization with Keysight VSA (1:30:28)
In this episode Shahriar takes a close look at the top-of-the-line Rigol DSA875-TG 7.5GHz Spectrum Analyzer. This unit which, offers a built in tracking generator for the full frequency range, has a portable form-factor. I offers the following performance:
9 kHz to 7.5 GHz Frequency Range
Typical -161 dBm Displayed Average Noise Level (DANL) normalized to 1 Hz
-98 dBc/Hz @10 kHz offset Phase Noise
Total Amplitude Uncertainty <0.8 dB
10 Hz Minimum Resolution Bandwidth (RBW)
The unit is tested against linearity specification as well as overload conditions. The phase noise of the unit is also verified with an external Keysight synthesizer. The instrument is used to measure OIP3, P1dB input and output matching of various amplifiers. The tracking generator is also used to measure gain and switching behavior of a WiFi extender module. The built-in functions are used to measure OBW, channel power, ACP and THD. The teardown of the unit is also presented showing excellent build quality and manufacturing.
The Signal Path (TSP) is an electrical engineering video blog for industry professionals, students and hobbyists. TSP is a non-for-profit website dedicated to provide free education spanning a wide range of electrical engineering topics. Equipment reviews, tutorials and repair videos are posted regularly.