US 12,332,297 B2
Test system
Bryan Edward Cole, Cambridge (GB)
Assigned to Tera View Limited, Cambridge (GB)
Filed by TeraView Limited, Cambridge (GB)
Filed on Jun. 15, 2023, as Appl. No. 18/335,360.
Application 15/991,543 is a division of application No. 13/984,980, granted, now 10,006,960, issued on Aug. 26, 2018, previously published as PCT/GB2012/050313, filed on Feb. 13, 2012.
Application 18/335,360 is a continuation of application No. 17/495,399, filed on Oct. 6, 2021, granted, now 11,726,136.
Application 17/495,399 is a continuation of application No. 15/991,543, filed on May 29, 2018, granted, now 11,169,202, issued on Nov. 9, 2021.
Claims priority of application No. 1102507 (GB), filed on Feb. 11, 2011.
Prior Publication US 2023/0324452 A1, Oct. 12, 2023
Int. Cl. G01R 31/28 (2006.01); G01R 31/11 (2006.01); G01R 31/308 (2006.01)
CPC G01R 31/28 (2013.01) [G01R 31/11 (2013.01); G01R 31/2822 (2013.01); G01R 31/308 (2013.01)] 9 Claims
OG exemplary drawing
 
1. A reflectometer for allowing a test of a device, the reflectometer comprising:
a source of pulsed radiation;
a first photoconductive element configured to output a pulse in response to irradiation from the source of pulsed radiation;
a choke resistor arranged such that the first photoconductive element is biased through the choke resistor, the choke resistor having a resistance of at least 100Ω;
a second photoconductive element configured to receive a pulse, wherein the second photoconductive element is configured as a receiver;
a transmission line arrangement configured to direct the pulse from the first photoconductive element to a device under test and to direct the pulse reflected from the device under test to the second photoconductive element, such that the second photoconductive element receives the pulse reflected from the device under test;
an amplifier configured to amplify the output of the second photoconductive element; and
a unit configured to provide an input AC impedance of at least 100,000 ohm at the AC bias frequency to the amplifier.