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Electronics Measurements

Low-noise Amplifiers

The frequency response of the low-noise amplifier was measured.

The response with 200 MHz was also measured. The 1 dB compression point was at -6.9 dBm input which corresponds to +13.9 dBm output. lnamp_power.png lnamp_phase.png

A second LNA was tested that works over a wider range but with a worse noise figure.

The response against CW input power at 200 MHz was also measured.

minilna_power.png minilna_phase.png

Third order intercept point measurements were also taken with various signal input parameters. The second measurement shows the best agreement with the 1 dB compression point measurement but the worst agreement with the data sheet value (+32 dBm).

Iteration IP3/dBm p1dB
1 2
1 32 31 22
2 29 26 18
3 30 30 20

ip3one.png ip3equal.png



The frequency response of the mixer was measured.


The response at 15.0 GHz RF and 14.8 GHz LO was also measured with a sweep in power of both the RF signal and the LO. The RF power was swept for a number of different input powers.

LO Power/dBm Gain/dB p1dB input/dBm p1dB output/dBm
+9 -11.9 +11.3 -1.7
+11 -9.4 +10.7 +0.2
+13 -9.1 +11.2 +1.1
+15 -9.1 +11.2 +1.1
+17 -9.1 +11.2 +1.1
At the recommended LO power of +13 dBm, the loss has stabilised to -9.1 dB while the input 1 dB compression point settles at +11.2 dBm. mixer_power.png mixer_lopower.png


750 MHz LPF

Frequency (left) and impulse (right) responses:

filter800MHz.png impr_750MHz.png

6700 MHz LPF

The 6700 MHz low-pass filter does not show optimal rejection around the 14.8 GHz LO frequency but it is still better than the 750 MHz low-pass filter in this region.

twofilters.png impr_6700MHz.png

300 MHz BPF

In this case, the time response has been undersampled.

filter300bpf.png impr_300mhzbpf.png

18 GHz LPF


20dB Coupler

Port Function
1 Input
2 Output
3 Coupled output

coupler_cpl.png coupler_ret.png

Cable loss against frequency


Attenuator control tests

Attenuator Attenuation Phase
HMC425LP3 (6-Bit) 6bitatt.png 6bitphase.png
HMC941LP4 (5-Bit) 5bitatt.png  

Reproducibility tests

The following histograms were populated by repeating measurements of attenuation magnitude and phase at each attenuation setting of the HMC425LP3. This was done 100 times and the residuals were calculated.
attrms.png pharms.png

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Topic revision: r15 - 11 Apr 2013 - JackTowler

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