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This version (10 Jun 2019 03:03) was approved by erbe.

AD-FMCOMMS11-EBZ Characteristics & Performance

Both Transmitter and Receiver were characterized independently. A comprehensive characterization suit of tests are reported upon herein. Characterization consists of SFDR, band flatness, IMD/ACLR and NSD measurements for each of the bands under consideration. These bands are 8 (925-960 MHz), 3 (1805 – 1880 MHz), 10 (2110 – 2170 MHz), 7 (2620 – 2690 MHz) and 22 (3510 - 3590 MHz).

Band TX Band (MHz) Expanded TX Band (MHz)
8 (GSM) 925-960 855-1030
3 (GSM) 1805-1880 1655-2030
10 (LTE) 2110-2170 1990-2290
7 (LTE) 2620-2690 2480-2830
22 (LTE) 3510-3590 3350-3750

The following equipment were used:

R&S SMA 100A signal gen (range:9kHz – 6GHz)

R&S®FSUP Signal Source Analyzer (upto 26.5GHz)

R&S ZND Vector Network Analyzer

11667B Power Splitter, DC to 26.5 GHz

K&L SPCL-00310 Microwave Tunable Filter (15 MHz to 4 GHz)

Receive Channel

Digital Step Attenuator (DSA) Frequency Response Test

The following images show the DSA (HMC1119) response with respect to the frequency with fix input power 9dBm and varying input frequency range (200MHz-6000MHz) of the receive channel. The table and image shows the following results:

Case Response
At -3dBFS Point 2150MHz
At 250MHz -1dBFs
At 4GMHz -11.4dBFs
At 6GHz -14.5dBFs

Another test was conducted by varying the attenuation level linearly with respect to a chosen input frequency from a signal generator. The table and image shows the following results:

DSA Sweep Frequency (MHz) (dBFS)
200 0.256
900 0.337
1800 0.29
2100 0.384
2600 0.55
6000 1.505

Single Tone Test

A single tone at three different power levels, -7, -13 and -19 dBm, is injected into a configurable band pass filter before going to the receiver input of the board to measure the NSD, SFDR, HD2 and HD3.

Noise Spectral Density (NSD) Test

The following figure shows the noise spectral density with varying input power in dBFs.

Spurious-Free Dynamic Range (SFDR) Test

The following figure shows the spurious-free dynamic range with varying input power in dBFs.

Single Tone 2nd Harmonic Distoriton (HD2) Test

The following figure shows the 2nd harmonic distoriton with varying input power in dBFs.

Single Tone 3rd Harmonic Distoriton (HD3) Test

The following figure shows the 3rd harmonic distoriton with varying input power in dBFs.

Two Tone Test

Two tones with 3 MHz in between spacing is swept across all bands at 5 MHz intervals at three different power levels -7, -13 and -19 dBm. The combined signal is the input to the K&L filter and the output of this filter will be the input to the ADC. IMD2, IMD3 and IMD5 performance is measured

Two SMA100A was used to produce the tones with 3 MHz spacing. These two tones are the inputs to the combiner which outputs the two tone signal combination. This two tone goes through the K&L filter to clean out any unnecessary noise before the ADC input.

Two Tone 2nd Order Intermodulation Distortion(IMD2) Test

The following figure shows the 2nd harmonic distoriton with varying input power in dBFs.

Two Tone 3rd Order Intermodulation Distortion(IMD3) Test

The following figure shows the 3rd harmonic distoriton with varying input power in dBFs.

Two Tone 5th Order Intermodulation Distortion(IMD5) Test

The following figure shows the 5th harmonic distoriton with varying input power in dBFs.

Return Loss (S11) Test

There are 4 test settings to be done and the VNA needs to be calibrated every time there is change in test settings. The settings for each test is shown in Table 1. These settings are for the VNA and DSA.

Test Parameters Test 1 Test 2 Test 3 Test 4
Range 10 MHz – 6 GHz 1 MHz – 4 GHz 10 MHz – 6 GHz 10 MHz – 6 GHz
Power -15 dBm -10 dBm -15 dBm -15 dBm
Points 1001 4000 1001 1001
Bandwidth 10 kHz 10 kHz 10 kHz 10 kHz
Scale 2 dB/div 5 dB/div 3 dB/div 3 dB/div
Reference level -16 dB -15 dB -24 dB -24 dB
DSA attenuation 0 dBm 0 dBm -10 dBm -31.75 dBm

The following figure shows the return loss obtained using R&S ZND Vector Network Analyzer(VNA).

Transmit Channel

Dual band tests were conducted as well as this architecture is thought to be conducive to multiband transmission. A set of band pairs where investigated through band flatness, SFDR and IMD/ACLR.

The following table shows the DAC settings used during the test.

DAC Parameters DAC Settings
F_dac_clock (MHz) 4915.2
Mode DDR On, Mix off
Interpolation 4x, complex
Bit rate per lane (Gbps) 6.144
Lanes 8
F_data(MSps) 1228.8
NCO Tes/band dependent

Output Frequency Band Flatness Test

The frequency response was analyzed. A single tone at -12 dBFS is swept from 20 MHz to 4.8 GHz in 2 MHz steps. For simplicity sake, the DAC was placed in NCO mode for this test.

Case Response
At 3dB Point 1.5GHz
At 6dB Point 4GHz
Flatness Range 1.5GHz - 3GHz

The following results show the flatness response of the DAC at different bands:

Band TX In-Band (dB) Expanded TX Band (MHz)
8 0.1 0.3
3 0.1 0.3
10 0.1 0.5
7 0.2 1.0
22 0.7 4.0

Spurious-Free Dynamic Range (SFDR) Test

SFDR was measured by stepping an integration interval over the expanded band of interest in Table 7. The integration bandwidth is 100 kHz or 5 MHz for GSM and LTE, respectively. For each sweep, the fundamental is stepped in 5 MHz increments by changing the NCO.

EDGE GSM vector properties LTE vector properties
Single carrier Single 5 MHz carrier
Centered on 0 Hz Centered on 0 Hz
PAR of 6.82 dB PAR of 10.52 dB
Plus digital back-off of 5.14 dB for -12 dBFS Plus digital back-off of 1.6 dB for -12 dBFS

Noise Spectral Density(NSD) Test

Block Diagram of the Test Setup

Noise spectral density was measured at an offset from a single tone, generated in NCO mode, at each band center. Measurement is done over an integration bandwidth of 500 kHz with a stock PXA without any special phase noise measurement module. Attenuation is set to 2-4 dB.

Inter-Modulation Distortion(IMD) Test

For IMD measurements, ACLR is used. The signals used are outlined in table below; they are the worst case IMD of each respective band. Only the band edges and the mid-band cases were measured. Graphs are shown below. Both the GSM and LTE vectors have a PAR of around 11 dB and are given one more dB of digital back-off to reach -12 dBFS. The NCO is used to place the signal to its final location.

Carrier Settings

Band # of TX Channel # of Adj channel Integration Bandwidth Carrier Separation
GSM 6 3 30KHz 600KHz
LTE 2 3 18MHz 40MHz

Shown below is the IMD performance with varying number of carrier for GSM band. This sweep was done at the center of band 8.

resources/eval/user-guides/ad-fmcomms11-ebz/hardware/card_specification.txt · Last modified: 22 Feb 2019 00:26 by erbe