| US 7,483,802 B2 | ||
| Linearisation apparatus | ||
| John Michael Wood, Essex (United Kingdom) | ||
| Assigned to BAE Systems plc., London (United Kingdom) | ||
| Appl. No. 11/628,249 PCT Filed May 27, 2005, PCT No. PCT/GB2005/050076 § 371(c)(1), (2), (4) Date Dec. 01, 2006, PCT Pub. No. WO2005/125061, PCT Pub. Date Dec. 29, 2005. |
||
| Claims priority of application No. 04136763.5 (GB), filed on Jun. 18, 2004; and application No. 04253674.8 (GB), filed on Jun. 18, 2004. | ||
| Prior Publication US 2007/0241805 A1, Oct. 18, 2007 | ||
| Int. Cl. G06F 19/00 (2006.01) | ||
| U.S. Cl. 702—86 [356/237.1] | 19 Claims |
| 1. A method of linearising a non-linear opto-electronic or electronic apparatus, the method comprising the steps:
(a) injecting one or more calibration tones as an input electrical signal and obtaining a digitised form of the output signal
of said apparatus;
(b) obtaining the spectrum of said digitised form and measuring, in the frequency domain, spectral values at the frequencies
of the input tone or tones and at the frequencies of spectral lines arising from the non-linearity;
(c) providing, from said spectral values, an inverse form of the non-linearity; and
(d) performing linearisation on subsequent output signals for arbitrary input signals by applying said inverse form of the
non-linearity to the output signal.
|