True Time Delay Optical Beamforming Network Based on Hybrid InP-Silicon Nitride Integration

Abstract

<div>We demonstrate a broadband and continuously tunable 1×4 optical beamforming network (OBFN), based on the hybrid integration of indium phosphide (InP) components in the silicon nitride (Si3N4) platform. The photonic integrated circuit (PIC) comprises a hybrid InP-Si3N4 external cavity laser, a pair of InP phase modulators, a Si3N4 optical single-sideband full carrier (SSBFC) filter followed by four tunable optical true time delay lines (OTTDLs), and four InP photodetectors. The performance of the OBFN-PIC is experimentally characterized by measuring the link gain, noise figure, and spurious free dynamic range of the microwave photonics links. Moreover, we assess its beamforming capabilities assuming that the OBFN-PIC is part of a wireless system operating in the downlink direction and feeds a multielement antenna array. Using microwave signals at 5 and 10 GHz with quadrature amplitude modulation (QAM) formats at 500 Mbaud, we evaluate the performance of the OBFN-PIC under various configurations. An error-free performance is achieved for all the experimental cases validating the potential of the proposed OBFN-PIC for high-quality beamforming performance. To our best of knowledge, this is the first thorough performance evaluation of a fully integrated OBFN-PIC.</div>

Transistor Laser Antenna: Electromagnetic Model in Transmit and Receive Modes

“…The unique features of conventional optical antennas were investigated in [2]- [4] and the references therein. Those investigations led to sophisticated designs and further studies on optical antennas for communications [5] and beamforming applications [6]- [8]. Furthermore, the characteristics of optical antennas in terms of circuit [9] or full-wave models [10] added extensive knowledge to the existing literature.…”

“…Following this, we need to determine the matrix element  of VCTL in (6) which is critical to couple the microscopic and macroscopic quantities [28]. To this end, both the ground and excited state wavefunctions are expanded by Bloch orthogonal basis functions as [28, Ch.…”

Chip-Based Brillouin Processing for Microwave Photonic Phased Array Antennas

“…At the same time, photonic integrated circuits (PICs), based on established semiconductor fabrication techniques, are enabling significant reductions to the footprint of MWP devices [22]- [27], opening possibilities for processing high frequency and wide bandwidth RF signals at every element of a PAA. Chip-based MWP devices have enabled demonstrations of numerous RF processing functionalities that could form the basis of future element-level processing required for PAAs, including agile RF filters [28], [29], phase shifters [30], [31] and true time delays (TTDs) for beam steering functionality, [32]- [34], frequency converters that interface between the operating RF and baseband frequencies [35], [36], and microwave sources [37]- [40]. Initial demonstrations of MWP beamforming networks highlight the potential for implementing chip-based beamforming for PAAs [32], [34], [41]- [44], expanded on below.…”

“…Chip-based MWP devices have enabled demonstrations of numerous RF processing functionalities that could form the basis of future element-level processing required for PAAs, including agile RF filters [28], [29], phase shifters [30], [31] and true time delays (TTDs) for beam steering functionality, [32]- [34], frequency converters that interface between the operating RF and baseband frequencies [35], [36], and microwave sources [37]- [40]. Initial demonstrations of MWP beamforming networks highlight the potential for implementing chip-based beamforming for PAAs [32], [34], [41]- [44], expanded on below.…”

Ultrahigh Dynamic Range and Low Noise Figure Programmable Integrated Microwave Photonic Filter

“…To play a key role in real RF applications, integrated MWP circuits need to simultaneously show advanced programmability and exceptional performance in terms of losses, noise figure, and dynamic range in a reduced footprint [3][4][5][6][7]. In recent pasts, a number of integrated MWP functions have widely been demonstrated, such as for filtering [8][9][10][11][12], phase shifting [13][14][15][16][17], delay line [18][19][20][21], waveform generator [22][23][24][25][26][27] and beamforming [28][29][30][31]. Typically, these functions were achieved in dedicated, or application specific circuits, and the measured RF metrics were only sparsely reported.…”