# Agilent 8648B 2 GHz Signal Generator (Pre-Owned)

# Agilent 8648B 2 GHz Signal Generator (Pre-Owned)

## Key Features At A Glance

-   Frequency coverage from 100 kHz to 4 GHz across the four models (8648A: 100 kHz–1 GHz; 8648B: 9 kHz–2 GHz; 8648C: 9 kHz–3.2 GHz; 8648D: 9 kHz–4 GHz)
-   0.001 Hz settable frequency resolution with 10 Hz display resolution across all four models
-   Output level range to –136 dBm with 0.1 dB display resolution for receiver sensitivity and low-level signal work
-   AM, FM, and phase modulation standard, with internal 400 Hz and 1 kHz sources plus external AC/DC modulation inputs
-   GPIB (IEEE-488.2-1987) remote programming with SCPI 1992.0 and 8656B/8657 code compatibility
-   Reverse power protection rated to 50 watts (≤2000 MHz) and 25 watts (≤4000 MHz) into 50 Ω
-   300 storage registers with up to 10 sequences of 30 registers each for repetitive test setups
-   Optional high-stability timebase (Option 1E5), high output power (Option 1EA), pulse modulation (Option 1E6), modulation generator (Option 1E2), and pager signaling (Option 1EP)

The Agilent 8648 Series Signal Generators are a four-model family of RF signal sources covering carrier frequencies from 9 kHz to 4 GHz, depending on model. The 8648A covers 100 kHz to 1 GHz; the 8648B extends to 2 GHz; the 8648C reaches 3.2 GHz; and the 8648D covers the full range to 4 GHz. All four share a common platform with 0.001 Hz settable frequency resolution, AM/FM/phase modulation, and GPIB remote programming.

A signal generator produces known, controllable RF signals used to stimulate or characterize other equipment. The 8648 series supports receiver testing, RF component characterization, transmitter alignment, and general-purpose stimulus for laboratory and production environments. With output ranges extending to –136 dBm and amplitude modulation depth from 0 to 100%, the family is configured for both high-level drive applications and low-level receiver sensitivity work.

## Brand Heritage

Agilent Technologies was spun out of Hewlett-Packard in 1999 when HP separated its test and measurement, life sciences, and chemical analysis businesses from its computing business. In 2014, Agilent further divided, with the electronic measurement business becoming Keysight Technologies. Instruments originally sold under the Agilent brand, including the 8648 series, trace through this lineage and are documented across HP, Agilent, and Keysight references depending on the production date.

## Compare Other Models in This Series

The Agilent 8648 series is a four-model family of RF signal generators sharing a common platform but differing in upper frequency limit. The 8648A covers 100 kHz to 1 GHz; the 8648B, 8648C, and 8648D extend the lower limit to 9 kHz and extend the upper limit to 2 GHz, 3.2 GHz, and 4 GHz respectively. Modulation capabilities, frequency resolution, and remote programming are common across all four.

Within the family, certain options are model-specific. The pager signaling option (1EP) is available only on the 8648A. The pulse modulation option (1E6) and the high output power option (1EA) are available only on the 8648B, 8648C, and 8648D. Option 1E5 (high-stability timebase) and Option 1E2 (modulation generator) are available across the full family.

Each pre-owned model below is listed as its own product page with condition-matched pricing, current inventory status, and the specific option configuration of the unit in stock. Confirm the frequency range and installed options against the requirements of the intended application before ordering.

The four 8648 models are distinguished primarily by upper frequency limit and by the lower frequency limit on the 8648A (100 kHz versus 9 kHz on the others). The output power range is also model-specific: the 8648A provides +10 to –136 dBm across its full range, while the 8648B/C/D provide +13 to –136 dBm up to 2500 MHz and +10 to –136 dBm above. With the high output power Option 1EA, the 8648B/C/D reach +20 dBm at frequencies through 1000 MHz.

Phase noise, residual FM, and modulation deviation ranges scale with frequency band. FM peak deviation, for example, increases from 200 kHz below 249 MHz to 800 kHz at frequencies up to 4000 MHz. The comparison table below summarizes the key differences across the family at a glance.

Model

Frequency Range

Max Output Power

Phase Noise (1 GHz, 20 kHz offset)

**8648B**

9 kHz to 2000 MHz

+13 dBm (≤2500 MHz)

<-116 dBc/Hz

8648A

100 kHz to 1000 MHz

+10 dBm

<-116 dBc/Hz

8648C

9 kHz to 3200 MHz

+13 dBm (≤2500 MHz)

<-116 dBc/Hz

8648D

9 kHz to 4000 MHz

+10 dBm (≤4000 MHz)

<-116 dBc/Hz

Additional differences in specifications beyond the few shown above are not listed here — see each model's full specifications below.

## Product Core & Specifications

Specification

Value

Frequency

Range (8648A)

100 kHz to 1000 MHz

Range (8648B)

9 kHz to 2000 MHz

Range (8648C)

9 kHz to 3200 MHz

Range (8648D)

9 kHz to 4000 MHz

Resolution (settable)

0.001 Hz

Resolution (display)

10 Hz

Accuracy

Typically ±3x10⁻⁶ × carrier frequency (Hz); ±0.15x10⁻⁶ × carrier frequency for Option 1E5

Switching speed (typical, <1001 MHz)

<75 ms

Switching speed (typical, ≥1001 MHz)

<100 ms

Internal Reference Oscillator

Aging (standard timebase, typical)

<±2 ppm/year

Aging (Opt 1E5 high stability)

<±0.1 ppm/year; <±0.0005 ppm/day

Temperature (standard)

<±1 ppm

Temperature (Opt 1E5, typical)

<±0.01 ppm

Line Voltage (standard)

<±0.5 ppm

Line Voltage (Opt 1E5, typical)

<±0.1 ppm

Output

10 MHz, typically >0.5 Vrms into 50 Ω

External reference input

2, 5, 10 MHz ±10 ppm typical (±1 ppm typical with Opt 1E5), 0.5 to 2 Vrms into 50 Ω

Spectral Purity

Harmonics (output ≤+4 dBm)

<-30 dBc

Subharmonics (<1001 MHz)

<-60 dBc

Subharmonics (≤3200 MHz)

<-50 dBc

Subharmonics (≤4000 MHz)

<-40 dBc

Nonharmonics (<249 MHz)

<-55 dBc

Nonharmonics (<1001 MHz)

<-60 dBc

Nonharmonics (<2001 MHz)

<-54 dBc

Nonharmonics (≤4000 MHz)

<-48 dBc

Residual FM (<249 MHz)

<7 Hz, typically <4 Hz

Residual FM (<501 MHz)

<4 Hz, typically <2 Hz

Residual FM (<1001 MHz)

<7 Hz, typically <4 Hz

Residual FM (<2001 MHz)

<14 Hz, typically <8 Hz

Residual FM (≤4000 MHz)

<28 Hz, typically <12 Hz

SSB phase noise at fc 500 MHz (20 kHz offset, typical)

<-120 dBc/Hz

SSB phase noise at fc 1000 MHz

<-116 dBc/Hz

SSB phase noise at fc 2000 MHz

<-110 dBc/Hz

SSB phase noise at fc 3000 MHz

<-106 dBc/Hz

SSB phase noise at fc 4000 MHz

<-104 dBc/Hz

Output

Range (8648A)

+10 to -136 dBm

Range (8648B/C/D, ≤2500 MHz)

+13 to -136 dBm

Range (8648B/C/D, ≤4000 MHz)

+10 to -136 dBm

Display resolution

0.1 dB

Accuracy (≤2500 MHz)

±1.0 dB

Accuracy (≤3200 MHz)

±1.5 dB

Accuracy (≤4000 MHz)

±2.0 dB

Reverse power protection (≤2000 MHz)

50 watts

Reverse power protection (≤4000 MHz)

25 watts

SWR (<249 kHz, typical)

<2.5:1

SWR (<2500 MHz, typical)

<1.5:1

SWR (≤4000 MHz, typical)

<2.0:1

Output impedance

Nominally 50 Ω

Maximum Leveled Power (High Power Option 1EA, 8648B/C/D only)

≤100 kHz

+17 dBm

≤1000 MHz

+20 dBm

≤1500 MHz

+19 dBm

≤2100 MHz

+17 dBm

≤2500 MHz

+15 dBm

≤4000 MHz

+13 dBm

Amplitude Modulation (fc >1.5 MHz)

Range

0 to 100% (output ≤+4 dBm)

Resolution

0.1%

Accuracy (1 kHz rate)

±5% of setting ±1.5%

External rates (DC)

DC to 25 kHz (typical, 3 dB BW)

External rates (AC)

1 Hz to 25 kHz (typical, 3 dB BW)

Distortion (30% AM, 1 kHz, THD+N)

<2%

Distortion (8648A at 90% AM)

<3%

Distortion (8648B/C/D at 70% AM)

<3%

Frequency Modulation

Peak deviation (<249 MHz)

0 to 200 kHz

Peak deviation (<501 MHz)

0 to 100 kHz

Peak deviation (<1001 MHz)

0 to 200 kHz

Peak deviation (<2001 MHz)

0 to 400 kHz

Peak deviation (≤4000 MHz)

0 to 800 kHz

Resolution (≤10% peak deviation, <2001 MHz)

10 Hz

Resolution (≤10% peak deviation, ≥2001 MHz)

20 Hz

Resolution (>10% to max, <2001 MHz)

100 Hz

Resolution (>10% to max, ≥2001 MHz)

200 Hz

Deviation accuracy (<1001 MHz)

±3% of FM deviation ±30 Hz

Internal rates

400 Hz or 1 kHz, or 10 Hz to 20 kHz with Opt 1E2

**Important:** Reverse power protection: 50 watts into 50 Ω at frequencies ≤2000 MHz, and 25 watts into 50 Ω at frequencies ≤4000 MHz.**Important:** Combining Option 1E6 with Option 1EA reduces maximum output power by 2 dB above 100 MHz. Below 100 MHz, maximum output is +13 dBm (typically +16 dBm for carrier frequencies between 100 kHz and 100 MHz).**Important:** Output power accuracy is valid from maximum specified output power to -127 dBm. Below -127 dBm, accuracy is typically ±3 dB in the range 100 kHz to 2500 MHz, and is not specified outside this frequency range.**Important:** Output power accuracy applies at 25°C ±5°C; it typically degrades up to ±0.5 dB over 0°C to 50°C or at output power levels >13 dBm.**Important:** All performance below a carrier frequency of 250 kHz is typical (not warranted).**Important:** Option 1E6 (Pulse Modulation) and Option 1EA (High Output Power) are not available on the 8648A.**Important:** Option 1EP (Pager Signaling) is only available on the 8648A.

## About this used unit

-   Warranty included
-   Functional verification included
-   Standard Calibration Upgrade Options: No Calibration Required, NIST Traceable, Z540.1 or ISO 17025 with Data, Z540.3 Guardbanding with Data.
-   Note that unnecessary accessories may not be included (contact Test Architect to confirm).

**Please review the Manufacturer's Data Sheet to verify published specifications. Feedback on this webpage is always welcome — please reach out to your Test Architect at any time for questions or concerns. Thank you, we truly appreciate you being our customer.**

## Details

- **Price:** 9300.0 USD - 10210.0 USD
- **Vendor:** Agilent
- **Type:** Rf Gen
- **Tags:** Agilent, Agilent Keysight, Manufacturers, product_manual_group_1, Product_used, RF, Signal Generators, Updated Item Review

## Variants

| Variant | Price | Available |
|---------|-------|-----------|
| None | 9300.00 USD | In stock |
| NIST Traceable | 9860.00 USD | In stock |
| NIST Traceable with Full Data | 10000.00 USD | In stock |
| ISO IEC 17025 Accredited | 10210.00 USD | In stock |

## Images

- 8648B Agilent RF Generator

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> Source: [ValueTronics](https://valuetronics.com/products/8648b-agilent-rf-generator-used)
> Updated: 2026-05-30