Photodiode chip having a high limit frequency
AssigneeFraunhofer-Gesellschaft zur Föderung der angewandten Forschung e.V.
InventorsHeinz-Gunter Bach, Andreas Beling
Life of this patent
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Abstract
The invention relates to a photodiode chip which has a great limit frequency and a junction from the active photodiode area of a photodiode mesa to the output pad of the high-frequency output of the photodiode chip. The aim of the invention is to further increase the bandwidth factor of photodiode chips. Said aim is achieved by establishing the connection from the photodiode mesa to the output pad by means of a high-resistance wire with impedance (Zleitung) which is spread across the length thereof and is at least as high as the load impedance (Zlast) effective at the output pad.
Claims18
A high frequency limit photodiode device comprising:
- a high frequency output pad having a load impedance (Zload) acting thereon;
- a photodiode mesa having an active photodiode region;
- and a transmission line connecting the photodiode mesa to the high frequency output pad;
- wherein the transmission line is a high-impedance transmission line having a length and an impedance (Zline) that is distributed over the length, and wherein the transmission line impedance (Zline) is at least as high as the load impedance (Zload) acting on the output pad;
- and
- wherein the length of the high-impedance transmission line is increased beyond a technologically required minimum value of approximately 30 μm.
A high frequency limit photodiode device comprising:
- a high frequency output pad having a load impedance (Zload) acting thereon;
- a photodiode mesa having an active photodiode region;
- and
- a transmission line connecting the photodiode mesa to the high frequency output pad;
- wherein the transmission line is a high-impedance transmission line having a length and an impedance (Zline) that is distributed over the length, and wherein the transmission line impedance (Zline) is at least as high as the load impedance (Zload) acting on the output pad;
- and
- wherein the impedance (Zline) of the high-impedance transmission line is at least twice as high as the load impedance (Zload).
Dependencies are inferred from the claim text.