IEC 62803 pdf download

IEC 62803 pdf download.Transmitting equipment for radiocommunication – Frequency response of optical-to-electric conversion device in high-frequency radio over fibre systems – Measurement method
1 Scope
This International Standard provides a method for measuring the frequency response of optical-to-electric conversion devices in wireless communication and broadcasting systems. The frequency range covered by this standard goes up to 1 00 GHz (practically limited up to 1 1 0 GHz by precise RF power measurement) and the wavelength band concerned is 0,8 µm to 2,0 µm.
2 Normative references
The following documents, in whole or in part, are normatively referenced in this document and are indispensable for its application. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. There are no normative references in this document.
3 Terms, definitions and abbreviations
3.1 Terms and definitions For the purposes of this document, the following terms and definitions apply. 3.1 .1 conversion efficiency ratio of the output current to the input optical power defined by
3.1 .2 two-tone lightwave lightwave that contains two dominant spectral components whose power difference is relatively small and frequency separation is stable Note 1 to entry: Undesired spectral components are suppressed significantly. The measurement methods described in this standard utilize a Mach-Zehnder modulator (MZM) for two-tone signal generation, where the MZM is biased at maximum or minimum transmission points (null or full bias) [1 ] 1 . The suppression ratio of undesired components depends on the on-off extinction ratio and chirp parameter of the MZM. By using active trimming, high extinction-ratio and low chirp modulation can be achieved for ideal two-tone generation (see Annex A). 3.1 .3 carrier-suppressed situation when an MZM is biased at its minimum transmission point, the non-modulated carrier lightwave transmitted through and the two arms of the MZM are cancelled with each other at the output coupler Note 1 to entry: The suppression ratio is related to how the two lightwaves in the two arms have the same power and to their anti-phase at the output coupler.
4 Optical-to-electrical (O/E) conversion device
4.1 Photo diode (PD) 4.1 .1 General A PD has a positive-negative (PN) junction which can be illuminated by an optical signal. When a photon is incident to the PN junction, an electron is excited and an electron-hole pair is generated. The electron and hole drift to the opposite direction because of the built-in and reverse-biased voltage at the PN junction, and can be used as an output electric current. 4.1 .2 Component parts The O/E conversion devices consist of basic parts as follows: – PD; – input fibre pigtail (where appropriate); – input receptacle (where appropriate); – output RF port (where appropriate); – bias electrode (where appropriate); – transimpedance amplifier (where appropriate); – impedance matching resistor (where appropriate). 4.1 .3 Structure The structure consists of the following (see Figure 2): – optical input: fibre pigtail or receptacle; – RF output: coaxial connector, microstrip line, coplanar waveguide, antenna, etc.; – options: bias electrode, transimpedance amplifier, impedance-matching resistor.4.1 .4 Requirements for PD 4.1 .4.1 General This method is based on a heterodyne principle. Requirements for the PD of this measurement method are as follows. 4.1 .4.2 Material of PD Main materials of the PDs should be Si, GaAs, and InGaAs. 4.2 DFG device 4.2.1 General When two coherent lightwaves are incident to a DFG device fabricated from a second order nonlinear optical material, an RF signal with the difference frequency between the incident lightwaves is generated. 4.2.2 Component parts The component parts are as follows: – DFG device; – input optical lens (where appropriate); – output RF antenna (where appropriate).
5 Sampling for quality control
5.1 Sampling A statistically significant sampling plan shall be agreed upon by user and supplier. Sampled devices shall be randomly selected and representative of production population, and shall satisfy the quality assurance criteria using the proposed test methods. 5.2 Sampling frequency Appropriate statistical methods shall be applied to determine adequate sample size and acceptance criteria for the considered lot size. In the absence of more detailed statistical analysis, the following sampling plan can be employed. Sampling frequency for evaluation of frequency response: two units at least per manufacturing lot.