Rhode and Schwarz Presentations - Long Island 10/24/2023 Presentation 1: James  - EmC presentations - gtime FFT  - Emissions  Summary:  - Compliance testing is required for most electrical devices  - Failure rate in full compliance is quite  high  - Redesign + retest is retired  - Precompliance testing is very important  Questions:  - Anyone melted a probe? (people have definitely melted antennas)  --- Signal Generators  Topics:  - Primary purpose of signal generators  - Produces electrical wave forms of various a mplitudes, frequency and phase properties  - Signal sinusoidal (CW - Continuous wave, SMW-2WA - the “flagship” Signal Generator)  Why are they important?  - They provide close to ideal input signals to the device under test (DUE_  - They emulate real-worls signals in the case of complex - moulations 5G, LTE, Wifi  - Good performance ois important to minimize generators  Signal Generators → 1. Analog Generators 2. Digital Generators  Analog Signal Generators  - Frequency, basic modulation, boise and spectral p - Major reason for switching to analog  Veector Signal Generators  - Frequency and level range  - Noise and spectral purity → modulation BW + capabilities  Analog  (insert image here)  Vector  (insert image here)   What do we need an analog generator for  - High quality singals  - Reference code  - Gain  - Component development / testing (ADCD_  - Receiver testing  - Military / radar applications  AM  Frequency modulation    FM frequency modulation Phase freqeuncy modulation  Analog Generator Selection Criterai -- things to consider  Primary:  - Frequency range  - Phase-noise  - Harmonics  - Output power  Secondary - Switching speeds  - Frequency + amplitude accuracy  - Very bad modulation support  - Very important to understand your input signals  Vector Signal Generator Applciations  - Receiver testing - a huge applications  - Impairment generation  - Impulse testing  - Fading capbiliites, ability to generate attenuated delayed signals  - Radar echo preparations (GNSS) - Multipath signal generators Vecotr Signal Basics:  - Analog signals defined by magnitude  - Vector signals defined by: magnitude + phase  - Used in digita modulation  - LTE, SGNR, Wifi, Bluetooth, SatCOM  ASK, PSK, FSK  Generating IQ Values  - Start with Symbol that represents particular magnitude _ phase  - Magnitude + phase can be converted into can be converted into  - In-phase (“real”)  - Quadratic (“imaginary”)  - Simplifies the pair of IQ vzlaues  IQ Modulatior  - Converts base band (transmitting) signals into RF Signals  - This allows the AM FM PM to sum the signals  IQ Modulation Steps   - Many licensing keys that you buy/input  - ca n bring data in digitally (bring the IQ values in digitally) - various  ways to define the baseband  - Can have a file of IQ values  - Specific data that has been mapped to IQ values  - Appropriate IQ values are generated based on what you selected  - Seiteis fo steps involved in creating a vector modulated signal  - Basic Digital Modulation - each variations of a signal magnitude _ phase represent a unique symbol  - Each symbol  represents a specific  digital bit or combination of  bits  -  ASL - Amplitude  of  100%  and 50%  BPSK - phase 0 degrees and 180 degrees  Constellations (Symbol Mapping)  - Constellations - collection of symbols on a polar chart representing a signal and magnitude and phase  - X - acist depicting amplitude (I )  - Y -  as  depicting phase (Q)  - ASK depicts 2 symbols with 1 bit of info - modulating in amplitude  - BPSK chart depicts 2 symbols molulating only in phase  How do we add more bits/symbols/information for faster data transmission?  - Through QAM symbol mapping  - Could transmit only 1 bit previously can transmit 4 bits now!  - These mits make up the frame of  our wifi, transmission, bluetooth, etc..  Modulation Bandwidth  - Some LTE at least 10 MHz of bandwidth requires  - Frequency - generators RF frequency , usually the carrier signal  - Bandwidth  - ** important tto distinguish what the signal rate is and what the bit-rate is ** - Flatness is the gain variation of the  platform  Impairment Generation  - Another huge reason for vector  - previously  talked about band base generation  - Able to do fading and noise injection  (include image here)  - impairment s emulate real-world effects  - Keeps up with standards as well  - Base band impairments - noise - SW interferes - impulse noise - phase noice -  - Fading - ability t o generate copies of a signal , attenuate them, or dopplegang them  AWFN impairments  - Additive white gaissian noise additive - - Additive Combine dwith useful  - White: noise constant other frequency  - Gaussian - describes how noise changes over time ODFM (orthogonal)  - 23 ASK Constellations   ODFM orthogonal   - Considered more immune than QM  - Device under test → mini circuits amplification  AWGN Generation  - Constellation drawn by the analyzer  - Analyzer (receiver basically) no trouble achieving  - Signal to rnoise ratio - APSK (PVB -52, Digital Viceo Broad cast  - This  is  very important for devices that  are  re-timing the circuit  - Needs to be able to filter out the (phase) noise that you inject  Phase noise impairment: - Anything coming up in time domain (called jitter)  - Anything long0term in time domain (called wonder)  - Excessive phase noise can cause many issues  - Disturbance  in communication systems for instance - Phase noise can be addes to base bands signal by  - Define amount of phase noise at gain  - frequency offsets  - Adding phase noise to signal leads to rotation - Errors → adjacent signal  /  symbols  bleeding into other symbols - bit-error  Impulse Noise impairment - many real wprld examples of impulse noise impairment  - unintentional - spark plugs motors,  - Intentional - radars, or bursty , modulation time  Fading:**