RF Signal Generators SG380 Series — DC to 2 GHz, 4 GHz and 6 GHz analog signal generators SG380 Series RF Signal Generators Introducing the new SG380 Series RF Signal Generators — · DC to 2 GHz, 4 GHz or 6 GHz finally, high performance, affordable RF sources. · 1 µHz resolution The SG380 Series RF Signal Generators use a unique, innovative architecture (Rational Approximation Frequency Synthesis) to deliver ultra-high frequency resolution (1 µHz), · AM, FM, ΦM, PM and sweeps excellent phase noise, and versatile modulation capabilities (AM, FM, ΦM, pulse modulation and sweeps) at a fraction of · OCXO timebase (std.) the cost of competing designs. · −116 dBc/Hz SSB phase noise The standard models produce sine waves from DC to (20 kHz offset, f = 1 GHz) 2.025 GHz (SG382), 4.05 GHz (SG384) and 6.075 GHz (SG386). There is an optional frequency doubler (Opt. 02) · Rubidium timebase (opt.) that extends the frequency range of the SG384 and SG386 to 8.10 GHz. Low-jitter differential clock outputs (Opt. 01) are available, and an external I/Q modulation input (Opt. 03) is · Square wave clock outputs (opt.) also offered. For demanding applications, the SG380 Series can be ordered with a rubidium timebase (Opt. 04). · Analog I/Q inputs (opt.) On the Front Panel · Ethernet, GPIB, and RS-232 The SG380 Series Signal Generators have two front-panel outputs with overlapping frequency ranges. A BNC provides outputs from DC to 62.5 MHz with adjustable offsets and · SG382 ... $3,900 (U.S. list) amplitudes from 1 mV to 1 Vrms into a 50 Ω load. An N-type output supplies frequencies from 950 kHz to the upper · SG384 ... $4,600 (U.S. list) frequency limit of each model, with power from +16.5 dBm to –110 dBm (1 Vrms to 0.707 µVrms) into a 50 Ω load. · SG386 ... $5,900 (U.S. list) Stanford Research Systems phone: (408)744-9040 www.thinkSRS.com SG380 Series RF Signal Generators Modulation SG380 Series Phase Noise vs. Offset Frequency The SG380 Signal Generators offer a wide variety of modulation capabilities. Modes include amplitude modulation -40 (AM), frequency modulation (FM), phase modulation (ΦM), -50 and pulse modulation. There is an internal modulation -60 source as well as an external modulation input. The internal Offset modulation source produces sine, ramp, saw, square, and noise -70 waveforms. An external modulation signal may be applied to -80 the rear-panel modulation input. The internal modulation -90 generator is available as an output on the rear panel. -100 4 GHz Unlike traditional analog signal generators, the SG380 Series -110 1 GHz can sweep continuously from DC to 62.5 MHz. And for -120 frequencies above 62.5 MHz, each sweep range covers more 100 MHz than an octave. 10 MHz -130 -140 OCXO or Rubidium Timebase -150 10 100 1,000 10,000 100,000 1,000,000 10,000,000 The SG380 Series come with a oven-controlled crystal Frequency Offset (Hz) oscillator (OCXO) timebase. The timebase uses a third- overtone stress-compensated 10 MHz resonator in a thermostatically controlled oven. The timebase provides very The SG380 Series always synthesizes a frequency in low phase noise and very low aging. An optional rubidium the top octave and digitally divides to generate outputs oscillator (Opt. 04) may be ordered to substantially reduce at lower frequencies. Doing so creates phase noise frequency aging and improve temperature stability. characteristics which scale with output frequency by 6 dB/octave or 20 dB/decade. The internal 10 MHz timebase (either the standard OCXO or the optional rubidium reference) is available on a rear-panel The low phase noise at small offsets (for output. An external 10 MHz timebase reference may be example, –80 dBc/Hz at 10 Hz offset from 1 GHz) supplied to the rear-panel timebase input. is attributable to the low phase noise OCXO timebase reference oscillator. An important figure of merit for Square Wave Clock Outputs communications applications is the phase noise at 20 kHz offset, which is about –116 dBc/Hz at 1 GHz. Optional differential clock outputs (Opt. 01) are available on the rear panel which makes your SG380 a precision clock Differential Clock Outputs Amplitude Modulation (100 %) Option 01 provides differential clock outputs in The frequency range of the SG380 Series extends from addition to sine outputs. The clocks have transition DC to 2 GHz, 4 GHz or 6 GHz (depending on model). times of about 35 ps. Both the offset and amplitude of All of the analog modulation modes also extend to DC the clock outputs can be adjusted for compliance with allowing your SG380 to perform function generator standard logic levels. Shown here at 2 ns/division: tasks. Shown here is a 20 kHz carrier being amplitude 100 MHz front-panel sine wave output (top trace) modulated by a 1 kHz sine. and differential clock outputs (bottom traces). The displayed transition times are limited by the 1.5 GHz Top trace: Modulation output bandwidth of the oscilloscope. Bottom trace: Front-panel BNC output Stanford Research Systems phone: (408)744-9040 www.thinkSRS.com Phase Noise (dBc/Hz) SG380 Series RF Signal Generators generator in addition to a signal generator. Transition times Output Frequency Doubler are typically 35 ps, and both the offset and amplitude of the clock outputs can be adjusted for compliance with PECL, The SG384 and SG386 can be ordered with a frequency doubler ECL, RSECL, LVDS, CML, and NIM levels. (Opt. 02) that extends the frequency range to 8.10 GHz. The amplitude of the rear-panel RF output can be adjusted from I/Q Inputs –10 dBm to +13 dBm. This option also comes with a bias source output which can be set with 5 mV resolution over Optional I/Q inputs (Opt. 03) allow I & Q baseband signals to ±10 VDC. modulate carriers from 400 MHz to the upper frequency limit of your instrument. This option also allows the I/Q modulator Easy Communication to be driven by an internal noise generator with adjustable bandwidth. Rear-panel outputs allow the noise source to be Remote operation is supported with GPIB, RS-232 and viewed or used for other purposes. Ethernet interfaces. All instrument functions can be controlled and read over any of the interfaces. Up to nine instrument configurations can be saved in non-volatile memory. I/Q Modulation of 1 GHz Carrier by Internal Noise Generator A New Frequency Synthesis Technique The SG380 Series Signal Generators are based on a new frequency synthesis technique called Rational Approximation Frequency Synthesis (RAFS). RAFS uses small integer divisors in a conventional phase-locked loop (PLL) to synthesize a frequency that would be close to the desired frequency (typically within ±100 ppm) using the nominal PLL reference frequency. The PLL reference frequency, which is sourced by a voltage controlled crystal oscillator that is phase locked to a dithered direct digital synthesizer, is adjusted so that the PLL generates the exact frequency. Doing so provides a high phase comparison frequency (typically 25 MHz) yielding low phase noise while moving the PLL reference Option 03 allows I/Q modulation of carriers spurs far from the carrier where they can be easily removed. from 400 MHz to the upper frequency limit of your The end result is an agile RF source with low phase noise, instrument. Two signal sources may be used for I/Q essentially infinite frequency resolution, without the spurs of modulation: external I & Q inputs or an internal fractional-N synthesis or the cost of a YIG oscillator. noise generator. The external I & Q BNC inputs are on the rear panel. The internal noise generator has adjustable noise bandwidth. Shown here is a 1 GHz carrier being modulated by the internal noise generator with 1 kHz noise bandwidth. Spectrum of Frequency Modulated 50 MHz Carrier Unmodulated Spectrum of a 1 GHz Output Outputs below 62.5 MHz are generated by direct- digital synthesis with a sample frequency of 1 GHz. In this example, a 50 MHz carrier is frequency modulated The SG380 Series outputs exhibit low phase noise and at a rate of 10 kHz and a deviation of 24.0477 kHz, low spurious content. In this direct measurement taken for a modulation index β = 2.40477. The carrier with 100 Hz RBW, the noise floor of the spectrum amplitude is proportional to the Bessel function J (β), 0 analyzer dominates over most of the 200 kHz span. which has its first zero at 2.40477. Stanford Research Systems phone: (408)744-9040 www.thinkSRS.com SG380 Series RF Signal Generators Polar Plot of 1.000001 GHz Referenced to 1 GHz with 100 % AM at 5 kHz The polar plot shows the trajectory of a signal in the Ordering Information I/Q plane. An unmodulated carrier at the analyzer’s SG382 2 GHz signal generator $3,900 reference frequency (1 GHz in this case) appears as a SG384 4 GHz signal generator $4,600 single dot in the I/Q plane. When the carrier frequency SG386 6 GHz signal generator $5,900 is offset, the single dot moves in a circle about the center of the I/Q plane. The pattern shown occurs Option 01 Rear-panel clock outputs $750 when the carrier amplitude is modulated with 100 % Option 02 8 GHz doubler & DC bias $750 depth at a rate of five times the carrier offset frequency (SG384 and SG386 only) (creating five lobes). The symmetry of the lobes Option 03 External I/Q modulation $750 indicates that there is no residual phase distortion Option 04 Rubidium timebase $1500 (AM to ΦM conversion) in the amplitude modulator. RM2U-S Single rack mount kit $100 The narrow line of the trajectory is indicative of low RM2U-D Dual rack mount kit $100 phase and amplitude noise. SG384 rear panel SG384 front panel Stanford Research Systems phone: (408)744-9040 www.thinkSRS.com SG380 Series Specifications 20 kHz offset –116 dBc/Hz (SG382 & SG384) SG380 Series Specifications –114 dBc/Hz (SG386) 1 MHz offset –130 dBc/Hz (SG382 & SG384) Frequency Setting –124 dBc/Hz (SG386) Residual FM (typ.) 1 Hz rms (300 Hz to 3 kHz BW) Frequency ranges DC to 62.5 MHz (BNC output, all models) Residual AM (typ.) 0.006 % rms (300 Hz to 3 kHz BW) SG382 950 kHz to 2.025 GHz (N-type output) SG384 950 kHz to 4.05 GHz (N-type output) * Spurs, phase noise and residual FM scale by 6 dB/octave to other 4.05 GHz to 8.1 GHz (w/ Opt. 02) carrier frequencies SG386 950 kHz to 6.075 GHz (N-type output) 6.075 GHz to 8.1 GHz (w/ Opt. 02) Phase Setting on Front-Panel Outputs Frequency resolution 1 µHz at any frequency Switching speed <8 ms (to within 1 ppm) –18 Max. phase step ±360º Frequency error <(10 + timebase error) × f C –11 Phase resolution 0.01º (DC to 100 MHz) Frequency stability 1 × 10 (1 s Allan variance) 0.1º (100 MHz to 1 GHz) 1.0º (1 GHz to 8.1 GHz) Front-Panel BNC Output Standard OCXO Timebase Frequency range DC to 62.5 MHz Amplitude 1.00 Vrms to 0.001 Vrms rd Oscillator type Oven controlled, 3 OT, SC-cut crystal Offset ±1.5 VDC Stability (0 to 45 ºC) <±0.002 ppm Offset resolution 5 mV Aging <±0.05 ppm/year Max. excursion 1.817 V (amplitude + offset) Amplitude resolution <1 % Rubidium Timebase (Opt. 04) Amplitude accuracy ±5 % Harmonics <–40 dBc rd Oscillator type Oven controlled, 3 OT, SC-cut crystal Spurious <–75 dBc Physics package Rubidium vapor frequency discriminator Output coupling DC, 50 Ω ±2 % Stability (0 to 45 ºC) <±0.0001 ppm User load 50 Ω Aging <±0.001 ppm/year Reverse protection ±5 VDC Timebase Input Front-Panel N-Type Output Frequency 10 MHz, ±2 ppm Frequency range Amplitude 0.5 to 4 Vpp (–2 dBm to +16 dBm) SG382 950 kHz to 2.025 GHz Input impedance 50 Ω, AC coupled SG384 950 kHz to 4.050 GHz SG386 950 kHz to 6.075 GHz Timebase Output Power output SG382 +16.5 dBm to –110 dBm Frequency 10 MHz, sine SG384 +16.5 dBm to –110 dBm (<3 GHz) Source 50 Ω, DC transformer coupled SG386 +16.5 dBm to –110 dBm (<4 GHz) Amplitude 1.75 Vpp ±10 % (8.8 dBm ± 1 dBm) Voltage output SG382 1.5 Vrms to 0.7 µVrms Internal Modulation Source SG384 1.5 Vrms to 0.7 µVrms (<3 GHz) SG386 1.5 Vrms to 0.7 µVrms (<4 GHz) Waveforms Sine, ramp, saw, square, pulse, noise Power resolution 0.01 dBm Sine THD –80 dBc (typ. at 20 kHz) Power accuracy ±1 dB Ramp linearity <0.05 % (1 kHz) Output coupling AC, 50 Ω Rate 1 µHz to 500 kHz User load 50 Ω (f ≤ 62.5 MHz (SG382 & SG384)) VSWR <1.6 C (f ≤ 93.75 MHz (SG386)) Reverse protection 30 VDC, +25 dBm RF C 1 µHz to 50 kHz (f > 62.5 MHz (SG382 & SG384)) Spectral Purity of the RF Output Referenced to 1 GHz* C (f > 93.75 MHz (SG386)) C Rate resolution 1 µHz Sub harmonics None 31 Rate error 1:2 + timebase error Harmonics <–25 dBc (<+7 dBm, N-type output) Noise function White Gaussian noise (rms = dev / 5) Spurious Noise bandwidth 1 µHz < ENBW < 50 kHz <10 kHz offset <–65 dBc Pulse generator period 1 µs to 10 s >10 kHz offset <–75 dBc Pulse generator width 100 ns to 9999.9999 ms Phase noise (typ.) Pulse timing resolution 5 ns 10 Hz offset –80 dBc/Hz 5 19 Pulse noise function PRBS 2 – 2 . Bit period (100 + 5N) ns 1 kHz offset –102 dBc/Hz Stanford Research Systems phone: (408)744-9040 www.thinkSRS.com SG380 Series Specifications Modulation Waveform Output Ext. FM carrier offset <1:1,000 of deviation Modulation bandwidth 500 kHz Output impedance 50 Ω (for reverse termination) (f ≤ 62.5 MHz (SG382 & SG384)) C User load Unterminated 50 Ω coax (f ≤ 93.75 MHz (SG386)) C AM, FM, ΦM ±1 V for ± full deviation 100 kHz Pulse/Blank “Low” = 0 V, “High” = 3.3 VDC (f > 62.5 MHz (SG382 & SG384)) C (f > 93.75 MHz (SG386)) C External Modulation Input Frequency Sweeps (Phase Continuous) Modes AM, FM, ΦM, Pulse, Blank Unmodulated level 0 V input for unmodulated carrier Frequency span 10 Hz to entire sweep range AM, FM, ΦM ±1 V input for ± full deviation Sweep ranges Modulation bandwidth >100 kHz SG382 & SG384 DC to 64 MHz Modulation distortion <–60 dB 59.375 MHz to 128.125 MHz Input impedance 100 kΩ 118.75 MHz to 256.25 MHz Input offset <500 µV 237.5 MHz to 512.5 MHz Pulse/Blank threshold +1 VDC 475 MHz to 1025 MHz 950 MHz to 2050 MHz Amplitude Modulation 1900 MHz to 4100 MHz (SG384) 3800 MHz to 8200 MHz (Opt. 02) Range 0 to 100 % (decreases above +7 dBm) SG386 DC to 96 MHz Resolution 0.1 % 89.0625 MHz to 192.188 MHz Modulation source Internal or external 178.125 MHz to 384.375 MHz Modulation distortion 356.25 MHz to 768.75 MHz BNC output <1 % (f < 62.5 MHz, f = 1 kHz) 712.5 MHz to 1537.5 MHz C M N-type output <3 % (f > 62.5 MHz, f = 1 kHz) 1425 MHz to 3075 MHz C M Modulation bandwidth >100 kHz 2850 MHz to 6150 MHz 5950 MHz to 8150 MHz (Opt. 02) Frequency Modulation Deviation resolution 0.1 Hz Sweep source Internal or external Frequency deviation Sweep distortion <0.1 Hz + (deviation / 1,000) Minimum 0.1 Hz Sweep offset <1:1,000 of deviation Maximum (SG382 & SG384) Sweep function Triangle, ramp or sine up to 120 Hz f ≤ 62.5 MHz Smaller of f or C C 64 MHz – f Phase Modulation C 62.5 MHz < f ≤ 126.5625 MHz 1 MHz C 126.5625 MHz < f ≤ 253.125 MHz 2 MHz Deviation 0 to 360º C 253.125 MHz < f ≤ 506.25 MHz 4 MHz Deviation resolution 0.01º to 100 MHz, 0.1º to 1 GHz, C 506.25 MHz < f ≤ 1.0125 GHz 8 MHz 1º above 1 GHz C 1.0125 GHz < f ≤ 2.025 GHz 16 MHz Deviation accuracy <0.1 % C 2.025 GHz < f ≤ 4.050 GHz (SG384) 32 MHz (f ≤ 62.5 MHz (SG382 & SG384)) C C 4.050 GHz < f ≤ 8.100 GHz (opt. 2) 64 MHz (f ≤ 93.75 MHz (SG386)) C C Maximum (SG386) <3 % f ≤ 93.75 MHz Smaller of f or (f > 62.5 MHz (SG382 & SG384)) C C C 96 MHz – f (f > 93.75 MHz (SG386)) C C 93.75 MHz < f ≤ 189.84375 MHz 1 MHz Modulation source Internal or external C 189.8437 MHz < f ≤ 379.6875 MHz 2 MHz Modulation distortion <–60 dB (f = 100 MHz, f =1 kHz, C C M 379.6875 MHz < f ≤ 759.375 MHz 4 MHz Φ = 50º) C D 759.375 MHz < f ≤ 1.51875 GHz 8 MHz Modulation bandwidth 500 kHz C 1.51875 GHz < f ≤ 3.0375 GHz 16 MHz (f > 62.5 MHz (SG382 & SG384)) C C 3.0375 GHz < f ≤ 6.075 GHz 32 MHz (f > 93.75 MHz (SG386)) C C 6.075 GHz < f ≤ 8.100 GHz (opt. 2) 64 MHz 100 kHz C Deviation resolution 0.1 Hz (f > 62.5 MHz (SG382 & SG384)) C Deviation accuracy <0.1 % (f > 93.75 MHz (SG386)) C (f ≤ 62.5 MHz (SG382 & SG384)) C (f ≤ 93.75 MHz (SG386)) Pulse/Blank Modulation C <3 % (f > 62.5 MHz (SG382 & SG384)) Pulse mode Logic “High” turns RF “on” C (f > 93.75 MHz (SG386)) Blank mode Logic “High” turns RF “off” C Modulation source Internal or external Modulation distortion <–60 dB (f = 100 MHz, f = f =1 kHz) C M D Stanford Research Systems phone: (408)744-9040 www.thinkSRS.com SG380 Series Specifications On/Off ratio BNC output 70 dB DC Bias Source (comes with Opt. 02) Type-N output 57 dB (f ≤ 1 GHz) C 40 dB (1 GHz ≤ f < 4 GHz) Output Rear-panel SMA C 35 dB (f ≥ 4 GHz) Voltage range ±10 V C Pulse feed-through 10 % of carrier for 20 ns at turn on (typ.) Offset voltage <20 mV Turn on/off delay 60 ns DC accuracy ±0.2 % RF rise/fall time 20 ns DC resolution 5 mV Modulation source Internal or external pulse Output resistance 50 Ω Current limit 20 mA External I/Q Modulation (Opt. 03) General Carrier frequency range 400 MHz to 2.025 GHz (SG382) 400 MHz to 4.05 GHz (SG384) Ethernet (LAN) 10/100 Base-T.TCP/IP & DHCP default 400 MHz to 6.075 GHz (SG386) GPIB IEEE488.2 Modulated output Front-panel N-type only RS-232 4800 to 115,200 baud, RTS/CTS flow I/Q inputs 50 Ω, ±0.5 V Line power <90 W, 90 to 264 VAC, 47 to 63 Hz w/ PFC I or Q input offset <500 µV Dimensions, weight 8.5" × 3.5" × 13" (WHD) 2 2 1/2 I/Q full scale (I + Q ) = 0.5 V Weight 10 lbs. Carrier suppression >40 dBc (>35 dBc above 4 GHz) Warranty One year parts and labor on defects in Modulation bandwidth 200 MHz (–3 dB) materials and workmanship Square Wave Clock Outputs (Opt. 01) Differential clocks Rear-panel SMAs drive 50 Ω loads Frequency range DC to 4.05 GHz Transition time (typ.) <35 ps (20 % to 80 %) Jitter f > 62.5 MHz <300 fs rms (typ., 1 kHz to 5 MHz BW C at 1 GHz) –4 f ≤ 62.5 MHz <10 U.I. (1 kHz to 5 MHz or f /2 BW) C C Amplitude 0.4 Vpp to 1 Vpp Offset ±2 VDC Ampl/offset resolution 5 mV Ampl/offset accuracy ±5 % Output coupling DC, 50 Ω ±2 % Compliance ECL, PECL, RSECL, CML, LVDS, NIM Frequency Doubler Output (Opt. 02) Output Rear-panel SMA Frequency range 4.05 GHz to 8.10 GHz (SG384) 6.075 GHz to 8.10 GHz (SG386) RF amplitude –10 dBm to +13 dBm (4.05 GHz to 7 GHz) –10 dBm to +7 dBm (7 GHz to 8.10 GHz) +13 to +16.5 dBm (spec. not guaranteed) Sub harmonic (f/2) <–25 dBc (f < 6.5 GHz) C C <–12 dBc (f < 8.1 GHz) C Mixing products (3f /2) <–20 dBc C Harmonics (n × f) <–25 dBc C Spurious (8 GHz) <–55 dBc (>10 kHz offset) Phase noise (8 GHz) –98 dBc/Hz at 20 kHz offset (typ.) Amplitude resolution 0.01 dBm Amplitude accuracy ±1 dB (4.05 GHz to 6.5 GHz) ±2 dB (6.5 GHz to 8.1 GHz) Modulation modes FM, ΦM, sweeps Output coupling AC, 50 Ω Reverse protection 30 VDC, +25 dBm RF Stanford Research Systems phone: (408)744-9040 www.thinkSRS.com