Table of Contents

D_Wafer

This is the lithium niobate wafer the allows testing of 91MHz designed tandsducers that are narrow and wide, long and short.

Test 1 - Angle Dependence

This test was done using the smallest 91MHz trandsucer in the bottom right corner. The yellow light was found to have minimal impact and so was left on. The red laser was used at 6V with a 28dBm signal coming from the amplifier (11.8 V to the amp). 94MHz was found to produce the maximum light deflection and 85MHz produced none.

Angle 85MHz 94MHz ▲W % Increase
11° 33.3µW 38.7µW 5.4µW 16.22%
21° 16.5µW 18.8µW 2.3µW 13.94%
31° 13.8µW 15.9µW 2.1µW 15.22%
40° 13.0µW 14.3µW 1.3µW 10.00%
51° 6.7µW 7.2µW 1.1µW 7.46%

Note: I had to change position of the wand between each angle and so inaccuracies were added. I believe that that is what accounts for the lager jump at 11. It appears that the smallest footprint (shallowest angle) provides the best interaction.

Test 2 - Spot Size

This test was done using the smallest 91MHz trandsucer in the bottom right corner. With the wafer at 21° off of normal. The yellow light was found to have minimal impact and so was left on. The red laser was used at 6V with a 28dBm signal coming from the amplifier (11.8 V to the amp). 94MHz was found to produce the maximum light deflection and 85MHz produced none.

Distance from Lens 85MHz 94MHz ▲W % Increase
80mm 18.5µW 21.5µW 3µW 16.22%
85mm 26.7µW 30.2µW 3.5µW 13.11%
87mm 22.1µW 25.9µW 3.8µW 17.19%
90mm 21.4µW 25.1µW 3.7µW 17.29%
95mm 22.6µW 25.7µW 3.1µW 13.72%
100mm 24.9µW 27.2µW 2.3µW 9.24%
105mm 25.1µW 26.4µW 1.3µW 5.18%
110mm 26.7µW 27.4µW 0.7µW 2.62%

Note: These required much less motion and should therefore be more accurate. At 110mm I could not see the change with my eye by knowing the pattern I placed the wand where it should go and ran the test anyway. It seems that tighter spots have a better interaction.

Test 3 - Distance to Transducer

This test was done using the smallest 91MHz trandsucer in the bottom right corner. With the wafer at 21° off of normal. The yellow light was found to have minimal impact and so was left on. The red laser was used at 6V with a 28dBm signal coming from the amplifier (11.8 V to the amp). 94MHz was found to produce the maximum light deflection and 85MHz produced none.

Distance from Transducer 85MHz 94MHz ▲W % Increase
0.3mm 32.3µW 37.4µW 5.1µW 15.79%
0.8mm 33.8µW 38.1µW 4.3µW 12.72%
1.3mm 66.5µW 71.3µW 4.8µW 7.22%
1.8mm 60.5µW 63.2µW 2.7µW 4.46%
2.3mm 60.8µW 63.4µW 2.6µW 4.28%
2.8mm 22.8µW 24.6µW 1.4µW 7.89%
3.3mm 22.2µW 24.0µW 1.8µW 8.11%
3.8mm 18.7µW 20.2µW 1.5µW 8.02%

Closer to the transducer as expected is better.

Test 4 - Transducer Length

This test was done using the smallest 91MHz trandsucer in the bottom right corner and the two other with the same width but x2 and x3 lenght. With the wafer at 21° off of normal. The measurements were made in the dark. The red laser was used at 6V with a 28dBm signal coming from the amplifier (11.8 V to the amp). 94MHz was found to produce the maximum light deflection and 85MHz produced none.

Transducer 85MHz 94MHz ▲W % Increase
x1 9.20µW 14.1µW 4.9µW 53.26%
x2 13.9µW 15.4µW 1.5µW 10.79%
x3 23.5µW 26.5µW 3.0µW 12.77%

This is not what was expected. It probably is caused by differences in independence matching.