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.

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.

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

Mixer

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.

Filters

750 MHz LPF

Frequency (left) and impulse (right) responses:

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.

300 MHz BPF

In this case, the time response has been undersampled.

18 GHz LPF

20dB Coupler

Port	Function
1	Input
2	Output
3	Coupled output

Cable loss against frequency

Attenuator control tests

Attenuator	Attenuation	Phase
HMC425LP3 (6-Bit)
HMC941LP4 (5-Bit)

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.