scholarly journals The Room Temperature Multi-Channel Heterodyne Receiver Section of the PHAROS2 Phased Array Feed

Electronics ◽  
2019 ◽  
Vol 8 (6) ◽  
pp. 666 ◽  
Author(s):  
Alessandro Navarrini ◽  
Alessandro Scalambra ◽  
Simone Rusticelli ◽  
Andrea Maccaferri ◽  
Alessandro Cattani ◽  
...  

This paper describes the design, fabrication, and test results of a room temperature multi-channel heterodyne receiver operating across the 2.3–8.2 GHz radio frequency (RF) band. Such a “Warm Section” (WS) receiver is part of phased arrays for reflector observing systems 2 (PHAROS2), a C-band phased array feed (PAF) demonstrator with digital beamformer for radio astronomy application. The WS receiver is cascaded to the PHAROS2 cryostat, which includes an array of Vivaldi antennas with low noise pre-amplification stages. The WS can handle up to 32 RF signals and, for each of them, realizes the operations of filtering, RF amplification and down-conversion from the RF to the 375–650 MHz intermediate frequency (IF). Also, the WS incorporates an IF-to-optical signal conversion through analogue wavelength division multiplexing IF over fiber (IFoF) and fiber-optic transmitters (OTXs). The 32-channel WS receiver consists of four eight-channel WS RF/IF modules, one local oscillator (LO) splitter module and one monitoring and control module, all hosted in a standard 6U × 19-inch rack.

Author(s):  
K. Ishikawa ◽  
Q. Yu

An integrated arrayed waveguide grating multi/demultiplexer (AWG) with a micro-electro-mechanical systems (MEMS) based variable optical attenuator (VOA) is reported. The device consists of an AWG based on silica and a MEMS-VOA chip. The MEMS chip includes 100 μm × 100 μm polysilicon shutter plates coated with gold and electrostatic comb-drive actuators. The MEMS chip is interposed in a trench located in the middle of the I/O waveguides of the AWG to tune the optical transmitting power intensity through the waveguides continuously. The MEMS-VOA shutters have more than a 10 μm displacement. Using those shutters, 30 dB optical contrast from 5 dB at the transmit state to 35 dB at the isolation state is achieved. The obtained attenuation contrast is greater than that of a conventional waveguide-based Mach-Zehnder interferometer VOA and sufficient to adjust and equalize the optical signal power in the wavelength division multiplexing (WDM) network systems.


2015 ◽  
Vol 25 (2) ◽  
pp. 147
Author(s):  
Bui Trung Ninh ◽  
Nguyen Quoc Tuan ◽  
Ta Viet Hung ◽  
Nguyen The Anh ◽  
Pham Van Hoi

We present the results of investigation  for  influence of amplified spontaneous emission (ASE) noise, noise figure (NF) and  chromatic dispersion on the performance of middle-distance Dense-wavelength-division-multiplexing (DWDM) networks using low-power pumped distributed Raman amplifiers (DRAs) in two different pump configurations, i.e., forward and backward pumping. We found that the pumping configurations, ASE noise, and dispersion play an important role for improving network performance by decrease of noise figure and bit error rate (BER) of the system. Simulation results show that the lowest bit error rate and low noise figure were obtained, when using forward pumping configuration. Moreover, we have also compared ASE noise powers of the simulation with these of the experiment. These results conclude that DRA with low pump power  ($<1$~W) is the promising key technology for short-- and/or middle-distance DWDM transmission networks.


2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Md. Asraful Sekh ◽  
Mijanur Rahim ◽  
Anjumanara Begam

Abstract In this paper, design of erbium-doped fiber amplifiers (EDFA) based 16 channel wavelength-division multiplexing (WDM) system for different pump powers and input signal levels using counter propagating pumping scheme is reported. Wavelength range between 1548 and 1560 nm in C-band with channel spacing of 0.75 nm at a bit rate of 10 Gbps are used. Input power given to all the channels is taken between −20 and −35 dBm with 3 dBm variation. Pump power levels between 100 and 500 mW at 980 nm wavelength are used. Low gain flatness with high gains and low noise figures are achieved with the proposed scheme.


Author(s):  
Anurupa Lubana ◽  
Sanmukh Kaur

In this paper, we present a novel erbium–ytterbium doped fiber amplifier (EYDFA) + Raman + EYDFA hybrid optical amplifier (HOA) for a super-dense wavelength division multiplexing (SD-WDM) system application. The performance of the 100-channel system has been investigated for an overall data rate and channel spacing of 100[Formula: see text]Gb/s and 0.4[Formula: see text]nm, respectively, over a wavelength span of 1550–1589.9[Formula: see text]nm. HOA has been optimized for Raman length, EYDFA lengths, pump powers and Er[Formula: see text] concentrations to achieve high average gain and low gain variation ratio of 40.41[Formula: see text]dB and 0.40[Formula: see text]respectively. The optimized configuration of the proposed HOA has been compared with EYDFA + Raman and Raman + EYDFA HOA configurations. The achieved high and flat gain with an acceptable output optical signal to noise ratio (OSNR) in case of EYDFA + Raman + EYDFA HOA; makes it an optimum choice for SD-WDM systems.


2019 ◽  
Vol 9 (19) ◽  
pp. 4059 ◽  
Author(s):  
Charoula Mitsolidou ◽  
Christos Vagionas ◽  
Agapi Mesodiakaki ◽  
Pavlos Maniotis ◽  
George Kalfas ◽  
...  

Analog fronthauling is currently promoted as a bandwidth and energy-efficient solution that can meet the requirements of the Fifth Generation (5G) vision for low latency, high data rates and energy efficiency. In this paper, we propose an analog optical fronthaul 5G architecture, fully aligned with the emerging Centralized-Radio Access Network (C-RAN) concept. The proposed architecture exploits the wavelength division multiplexing (WDM) technique and multicarrier intermediate-frequency-over-fiber (IFoF) signal generation per wavelength in order to satisfy the demanding needs of hotspot areas. Particularly, the fronthaul link employs photonic integrated circuit (PIC)-based WDM optical transmitters (Txs) at the baseband unit (BBU), while novel reconfigurable optical add-drop multiplexers (ROADMs) cascaded in an optical bus are used at the remote radio head (RRH) site, to facilitate reconfigurable wavelength switching functionalities up to 4 wavelengths. An aggregate capacity of 96 Gb/s has been reported by exploiting two WDM links carrying multi-IF band orthogonal frequency division multiplexing (OFDM) signals at a baud rate of 0.5 Gbd with sub-carrier (SC) modulation of 64-QAM. All signals exhibited error vector magnitude (EVM) values within the acceptable 3rd Generation Partnership Project (3GPP) limits of 8%. The longest reach to place the BBU away from the hotspot was also investigated, revealing acceptable EVM performance for fiber lengths up to 4.8 km.


2019 ◽  
Vol 40 (4) ◽  
pp. 347-351
Author(s):  
Chakresh Kumar ◽  
Rakesh Goyal

Abstract Analysis of proposed 400×10 Gbps super dense wavelength division multiplexing (SD-WDM) system has been evaluated in term of crosstalk and optical signal to crosstalk ratio (OSCR). Amplification is carried out using RAMAN-EDFA hybrid optical amplifier (HOA) for the transmission of 300 km. The pump power of 550 mW at 1520 nm and 580 mW at 1530 nm are set to RAMAN and EDFA optical amplifier respectively. Further, the power level of 0 dBm with channel spacing of 100 GHz has shown the remarkable outcome of controlling the fiber nonlinearity to maintain the best rating optical communication for long haul distance.


2019 ◽  
Vol 24 (5) ◽  
pp. 115
Author(s):  
Humam Husseinˡ ◽  
Dogu Cagdas Atilla1 ◽  
Essa Essa2 ◽  
Cagatay Aydin1

In recent years, there has been a growing and continuous demand for great (data rates) beyond existing wired and wireless networks. Radio-over-Fiber technology is considered as an efficient and practical solution for providing broadband wireless. In this paper, many techniques are used to implement a system that has the capability to provide a great bit rate, broadband bandwidth, and minimum cost. So Radio-over-Fiber technology was used to modulate the light with radio-signal and transmission the signals through an optical fiber cable. Wavelength-Division-Multiplexing technique was used to send many signals through the same link, and Subcarrier Multiplexing-Amplitude Shift keying as a modulation format. 2Gpbs separate on two channels was transmitted on Single-Mode Fiber. The average results obtained from our experience was as follows: maximum Q factor average = 4.9712925, minimum BER average = 3.63*10-7, total power average (dBm) = -51.1502, the OSNR average (dB) = 52.085 for channel_1. The results of channel_2 were: maximum Q factor average = 5.5901325, minimum BER average = 1.26*10-8, total power average (dBm) = -46.60135, the average of optical signal-to-noise ratio (dB) = 54.65. All the average result that has from our simulation was very good and acceptable. The simulation and performance test of our experience was done using Optisystem 7.0.   http://dx.doi.org/10.25130/tjps.24.2019.100


2017 ◽  
Vol 38 (1) ◽  
Author(s):  
F. H. Tithi ◽  
S. P. Majumder

AbstractAnalysis is carried out for a single span wavelength division multiplexing (WDM) transmission system with distributed Raman amplification to find the effect of amplifier induced crosstalk on the bit error rate (BER) with different system parameters. The results are evaluated in terms of crosstalk power induced in a WDM channel due to Raman amplification, optical signal to crosstalk ratio (OSCR) and BER at any distance for different pump power and number of WDM channels. The results show that the WDM system suffers power penalty due to crosstalk which is significant at higher pump power, higher channel separation and number of WDM channel. It is noticed that at a BER 10


2020 ◽  
Vol 41 (2) ◽  
pp. 171-176
Author(s):  
Harmanpreet Kaur Sandhu ◽  
R.S Kaler ◽  
Gurpreet Kaur ◽  
Rajneesh Randhawa

AbstractIn this article, the impact of cross-phase modulation (XPM) and cross-polarization modulation (XpolM) on transmission of 112 Gb/s polarization multiplexed quadrature phase shift keying (POLMUX QPSK) signal in a wavelength division multiplexing (WDM) system has been investigated. This WDM system comprises of on-off keying (OOK) or differential phase shift keying (DPSK) channels. It is observed that the effects of XPM and XpolM are greatly reduced in a hybrid system of co-propagating OOK and DPSK channels. This is due to the dominance of phase modulation of DPSK signals rather than the intensity modulated OOK signals. The error vector magnitude (EVM) of the received optical signal is evaluated for the increase in number of neighbouring OOK and DPSK channels respectively within a bandwidth of 350 GHz. Also, the effect of increase in bit rate for two neighbouring OOK and DPSK channels has been observed individually on the 112 Gb/s POLMUX QPSK signal. It is concluded that DPSK signals display an improvement of −9.44 dB in EVM over OOK signals when there are eight neighbouring channels in the transmission system.


2012 ◽  
Vol 4 (3) ◽  
pp. 283-289 ◽  
Author(s):  
Patricia Voll ◽  
Lorene Samoska ◽  
Sarah Church ◽  
Judy M. Lau ◽  
Matthew Sieth ◽  
...  

We report cryogenic noise temperature and gain measurements of a prototype heterodyne receiver module designed to operate in the atmospheric window centered on 150 GHz. The module utilizes monolithic microwave integrated circuit (MMIC) InP high electron mobility transistor (HEMT) amplifiers, a second harmonic mixer, and bandpass filters. Swept local oscillator (LO) measurements show an average gain of 22 dB and an average noise temperature of 87 K over a 40 GHz band from 140 to 180 GHz when the module is cooled to 22 K. A spot noise temperature of 58 K was measured at 166 GHz and is a record for cryogenic noise from HEMT amplifiers at this frequency. Intermediate frequency (IF) sweep measurements show a 20 GHz IF band with less than 94 K receiver noise temperature for a fixed LO of 83 GHz. The compact housing features a split-block design that facilitates quick assembly and a condensed arrangement of the MMIC components and bias circuitry. DC feedthroughs and nano-miniature connectors also contribute to the compact design, so that the dimensions of the moduleare approximately 2.5 cm per side.


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