Radio Frequency Spurious Suppression Ratio Research Articles

A Filterless Optical Generation Scheme of Frequency 32-Tupling Millimeter-Wave Signal Based on Cascaded Polarization Modulators

ABSTRACT In the work, a new method for generating a frequency 32-tupling millimeter-wave (mm-wave) signal with higher quality only using four polarization modulators (PolM) is proposed. To generate a pure 32-tupling mm-wave signal, it is necessary to beat ± 16th-order optical sidebands beat frequency. Mathematical calculations and simulation results both show that the scheme can obtain ± 16th-order harmonics, thereby generating frequency 32-tupling mm-wave signals. The optical sideband suppression ratio (OSSR) and radio frequency spurious suppression ratio (RFSSR) can reach 53.74 dB and 47.59 dB, respectively. Besides, the parameters that will affect OSSR and RFSSR are also analyzed and acceptable error ranges are provided.

Optical frequency multiplication using residual network with random forest regression

In this work, we present a method for optical frequency multiplication utilizing a hybrid deep learning approach that integrates the Residual Network (ResNet) with the Random Forest Regression (RFR) algorithm. Three different frequency multiplication modulation schemes are adopted to illustrate the method, which can obtain suitable parameters for these schemes. Based on the parameters predicted by the algorithm, the 8-tupling, 12-tupling, and 16-tupling mm-wave signals are generated by numerical simulation. The simulation results show that for 8-tupling frequency multiplication, an OSSR (optical sideband suppression ratio) is 30.73 dB and an RFSSR (radio frequency spurious suppression ratio) of 80 GHz is 42.29 dB. For 12-tupling frequency multiplication, the OSSR is 30.09 dB, and the RFSSR of the 120 GHz mm wave is 36.21 dB. For generating 16-tupling frequency mm-wave, an OSSR of 29.86 dB and an RFSSR of 34.52 dB are obtained. In addition, the impact of amplitude fluctuation and bias voltage drift on the quality of mm-wave signals is also studied.

Radio-over-fibre for generation and transmission32-tupling frequency optical millimeter wave with polarization modulators

Radio-over-fibre for generation and transmission32-tupling frequency optical millimeter wave with polarization modulators

A Novel Radio on Fiber System for Frequency 32-Tupling Millimeter-Wave Generation and Transmission Using Polarization Modulators

A new radio on fiber (ROF) scheme for generation and transmission frequency 32-tupling millimeter-wave (MMW) is proposed. At the central station (CS), six PoIMs are used to construct the ±16 order sidebands generator which can generate ±16 order sidebands. The sideband of +16th order is separate out by an optical interleaver from the output of ±16 order sidebands generator first, then the data of down-link signal is modulated on it. At the base station (BS), a portion sideband of −16th order from the down-link optical signal is separted out with a fiber Bragg grating (FBG) first, then the up-link data is modulated on it for carrier reuse. The remaining ±16th order sidebands from the FBG are beat in a photodetector (PD), then the frequency 32-tupling MMW signal with the down-link data is generated. The key part of this system is the ±16th order sideband generator, in which the ±16th order sidebands with the carrier component can be generated by adjusting the amplitudes and initial phases of the radio frequency (RF) signals loaded on the PoIMs, and the carrier can be cancelled by two 1×2 optical coupler with adjustable splitting ratio and 180° optical phase shifter (OPS). The principle of operation to generate frequency 32-tupling is theoretically analyzed and verified by simulation experiments. The optic sideband suppression ratio (OSSR) of the generated sidebands of ±16th order from the theoretical derivation and experiments are 29.974 dB and 29.793 dB, respectively, the RF spurious suppression ratio (RFSSR) of the obtained frequency 32-tupling MMW from theoretical derivation and experiment are 23.960 dB and 23.814 dB, respectively, which verifies the feasibility of our method. The transmission experiments are carried out. For 30 km fiber with 2.5 Gbps data rate, the Q value and power penalty for up-link and down-link are greater than 6 and less than 0.4 dB, respectively.

RF over fiber system for 5G application

5G communications involve the transfer of several Gb/s information in their small cells. The main solutions for high-speed data transfers for this objective are millimeter-wave RF signals. It is difficult to produce these high-frequency RF signals on the electrical field, so more study is given to the photonic generation of these signals. In this study, the utilization of a dual-drive Mach – Zehnder Modulator (DD-MZM) illustrates a special optical millimeter-wave(MMW) generation. A new method for producing a local oscillator frequency quadrupling optical carrier suppression (OCS) MMW signal utilize two equivalent DD-MZMs based on this form is shown. Data flow on a Radio over Fiber (RoF) network for transmission and generation of a 2.5 Gbps downlink, at OSSR (Optical Sideband Suppression Ratio) of up to 32 dB is acquired by simulation. The Radio Frequency Spurious Suppression Ratio (RFSSRR) is 22 dB

Research on 32-tupling frequency terahertz wave generation based on Mach-Zehnder modulators cascaded

A novel scheme to generate 32-tupling frequency terahertz waves by four Mach-Zehnder modulators (MZMs) cascaded is proposed. Four MZMs are divided into two groups linked in series and each group includes two MZMs connected in parallel. The output of the first group and second group of MZMs are ± 4nth and ± 8nth-order sideband signals, respectively. The 0th-order sideband can be cancelled by adjusting the splitting ratio of coupler; The ± 8th-order sidebands can be suppressed by adjusting the modulation index m of MZMs; The ± 8nth (n＞2) sidebands are negligible because of their very small amplitudes. Then the main components of output signal from the second group MZMs are ± 16th-order sidebands, which can generate 32-tupling frequency terahertz signal on the photodetector. The operation principle and simulation experiment of the proposed scheme is performed, and the optical sideband suppression ratio (OSSR) and radio frequency spurious suppression ratio (RFSSR) are obtained to be 53.7 dB, 53.34 dB and 47.7 dB, 47.39 dB, respectively. Simulation experiment values are very close to theoretical values and this demonstrates the feasibility of our scheme. The effects on the OSSR and RFSSR deviated from their designed values are investigated. When the deviations of modulation index, extinction ratio, DC bias, half-wave voltage, the insertion loss of MZM reach about ± 0.42 %, 82 %, ± 8.4 %, ± 1 %, 0.14 %, respectively, and when the deviations of initial phase of RF and splitting ratio of coupler reach about ± 1.3 % at 45°, ± 1.1 % at 90°, ± 2.27 %, respectively, the RFSSR are ≥ 15 dB, which satisfies the engineering applications

Generation of Therahertz Wave with Frequency 32-Tupling by Four Mach-Zehnder Modulators in Parallel

A new method for the generation of terahertz wave with frequency 32-tupling adopting four Mach-Zehnder modulators connected in parallel is presented. The four MZMs can be regarded as two double parallel Mach-Zehnder modulators (DPMZMs) connected in parallel. When the difference of the initial phases of the radio frequency (RF) driving signals between two MZMs in the DPMZM is π/2, the signal from the DPMZM are the optical sidebands of ±4n order. When the difference of initial phase of the RF signals between the two DPMZMs is π/4, the output signals from the two DPMZMs are the optical sidebands of ±8n order, in which the carrier is cancelled by an adjustable optical splitter, the optical sidebands of ±8th order are restrained and the optical sidebands of ±8n (n > 2) order are ignored by setting the modulation index of MZM at a special value, the main optical sidebands left are ±16th order. When the ±16th order optical sidebands are injected the photodetector (PD), the 32-tupling frequency terahertz wave is generated. Principle analysis and simulation test indicate that the optical sideband suppression ratio (OSSR) and the RF spurious suppression ratio (RFSSR) are 46.82 dB, 46.25 dB and 40.8 dB, 42.3 dB, respectively. In addition, the impacts on the OSSR and RFSSR are studied when the values of device parameters deviate from their design values.

A Filterless Generation of Optical Millimeter Wave Signal Based on Frequency 16-Tupling Using Cascaded Polarization Modulators

Millimeter wave (MMW) frequencies are becoming vital as they bolster a large number of applications requiring higher data rates. In this paper, we have demonstrated a frequency multiplication technique based on external modulation for a 160 GHz MMW signal generation. The proposed scheme which uses a four-stage cascaded structure of polarization modulators proves to be a lucrative solution since the selected modulation index of 2.826 is phenomenally low. A precise choice of phase shifts between the cascaded stages ensures two eighth-order peaks spaced 160 GHz apart. This technique renders Radio Frequency Spurious Suppression Ratio and Optical Sideband Suppression Ratio of 45 and 65 dB, respectively. Simulation results are verified from a mathematical standpoint. The requirement of a Radio Frequency Local Oscillator with a higher frequency has been eliminated by a higher value of frequency multiplication factor.

Generation of frequency 32-tupling millimeter-wave based on a dual-parallel polarization modulator.

A scheme to generate a frequency 32-tupling millimeter wave (mm-wave) is proposed, enabled by two dual-parallel polarization modulators (DP-PolMs) in cascade. By properly controlling the amplitude and the phase shift of the radio-frequency (RF) driving signal applied to two DP-PolMs, the main optical components at the output of the DP-PolM are ±16th order optical sidebands and the central carrier. After the central carrier is canceled by the polarization multiplexing structure, the ±16th order optical sidebands are beaten in the photodetector; then the frequency 32-tupling mm-wave can be achieved. The optical sideband suppression ratio (OSSR) and the radio-frequency spurious suppression ratio (RFSSR) of the generated signal are 52 and 47 dB in simulation, which are consistent with the theoretical analysis values 53.7 and 47.7 dB. The influence on the OSSR and RFSSR of the generated signal by the key parameters of devices deviating from the theoretical analysis value i are investigated.

Filterless frequency 16-tupling millimeter-wave signal generation with cascaded Mach–Zehnder modulators

A simple scheme is proposed for generating frequency 16-tupling millimeter-wave (MMW) signal based on cascaded Mach–Zehnder modulators (MZMs) and an optical phase shifter (PS) without optical filter. Theoretical analysis is given to generate the high-quality 16-tupling MMW signal by eliminating the undesired optical carrier and sidebands. Simulations show that the generated 16-tupling optical MMW signal has the optical sideband suppression ratio higher than 29.85 dB and radio frequency (RF) spurious sideband suppression ratio higher than 23.9 dB. The impact of non-ideal modulation index, extinction ratio, and phase difference of optical PS- and RF-driven signal applied to the cascaded MZMs are discussed and analyzed. After different lengths of fiber transmission, the generated optical MMW signal shows good performance. Furthermore, the influence of different laser linewidths on the transmission performance of the generated MMW signal is also performed and analyzed.

Photonic Generation of Frequency 16-Tupling Millimeter-Wave Signal without Optical Filter

A generalized optical filterless approach to achieve photonic generation of frequency 16-tupling millimeter-wave (mm-wave) signal based on two cascaded dual-parallel Mach-Zehnder modulators (DPMZMs) is presented. A theoretical analysis leading to the operating conditions to achieve frequency 16-tupling is developed. Different modulation indices (MIs) can be implemented to achieve the frequency multiplication by adjusting the delay of tunable optical delay line (TODL). It is confirmed by simulation that the proposed scheme is effective, and the radio frequency spurious suppression ratio (RFSSR) of the generated frequency 16-tupling signal can be as high as 40 dB when the sub-MZMs have extinction ratios of 30 dB. Influencing factors such as extinction ratio, DC bias drift, phase shift deviation and RF voltage deviation on the performance of optical sideband suppression ratio (OSSR) and RFSSR are also investigated.

Optical millimeter-wave generation via frequency octupling circuit based on two parallel dual-parallel polarization modulators

In this paper, a filterless optical millimeter-wave (mm-wave) generation by frequency octupling based on two parallel dual-parallel polarization modulators circuit is proposed. From the theoretical analysis, ± 4th order optical sidebands can be generated by proper adjustment of the phases of the radio-frequency (RF) drive signals and polarizer angle. Since there is no need for an optical filter to suppress the optical carrier or unwanted harmonics, the system is suitable for the optical generation of highly stable and tunable mm-waves. Theoretical analysis is verified by computer simulation. From the obtained results, it is shown that the optically generated mm-wave signal from the proposed circuit has a high optical sideband suppression ratio (OSSR) and radio-frequency spurious suppression ratio (RFSSR) for a wide range of modulation index. This range of modulation index extends, theoretically, from 1.8 up to 7.3. For instance, at a modulation index of 5.318, an 80 GHz can be generated from a 10 GHz RF drive signal with an OSSR of 68.4 dB and an RFSSR of 62 dB. Furthermore, the effects of non-ideal system parameters on the OSSR and RFSSR are investigated.

Filterless 16-tupling photonic millimeter-wave generation with Mach-Zehnder modulators using remodulation.

An optical millimeter-wave generation technique is presented in this paper. The system's two frequency quadruplers use dual-parallel Mach-Zehnder modulators. A 5 GHz radio frequency signal is fed to a quadrupler, which yields a 20 GHz signal after detection using a photodiode. The detected signal is used for remodulation of the other quadrupler, resulting in an 80 GHz signal with an optical sideband suppression ratio of 28 dB and a radio frequency spurious sideband suppression ratio of 27 dB. Further, the effect on the system performance in terms of the optical sideband suppression ratio and radio frequency spurious sideband suppression ratio with variation of various parameters is also evaluated. The optical sideband suppression ratio is well above 14 dB for a phase offset of ±9∘ in phase shifters with a modulation index range of 1.5-3.5 and an amplifier gain range of 25 dB to 32 dB.

Photonic 60 GHz sub-bands generation with 24-tupled frequency multiplication using cascaded dual parallel polarization modulators

Abstract An energy efficient and all optical 24 tupled radio frequency multiplication is proposed to generate 60 GHz using two cascaded dual parallel polarization modulators (DPPolMs). Detailed theoretical analysis is carried out using Jones matrix formalism. ±12th order optical sidebands are obtained at the output of second DPPolM which beat at the photo-detector (PD) to produce frequency 24 tupled RF carrier. A good optical spurious suppression ratio (OSSR) of 34.4 dB is obtained for ±12th order optical sidebands and radio frequency spurious suppression ratio (RFSSR) of 25.8 dB is obtained for 24-tupled RF signal. We verify the accuracy of the analysis with simulations in OptiSystem and a close match between theory and simulation results are obtained. We showed a scheme to generate four subcarrier signals in 57–64 GHz license free band using subcarrier multiplexing with an additional polarization modulator placed after cascaded DPPolMs. 10 km single mode fiber transmission performance of the optical sidebands in 57–64 GHz sub-band shows negligible power penalty of 0.3 dB at BER 10 - 9 .

Photonic generation of millimeter-wave signal through frequency 12-tupling using two cascaded dual-parallel polarization modulators

In this paper, filterless photonic generation of millimeter-wave (mm-wave) signal through frequency 12-tupling via two cascaded dual-parallel polarization modulators (DP-PolMs) is proposed. The principle of operation of the proposed system is theoretically analysed and verified by computer simulation. From the theoretical analysis, the frequency 12-tupling mm-wave signal is shown to be generated by properly adjusting the modulation indices of PolMs, polarization directions of the modulated optical signals, and the phases of the RF drive signals applied to the DP-PolM. The simulation results show that the generated frequency 12-tupling optical mm-wave has high purity with an optical sideband suppression ratio (OSSR) of 25.1 dB and radio frequency spurious suppression ratio (RFSSR) of 19.1 dB. Theoretically obtained results are in good agreement with the simulation results. Furthermore, taking into consideration the practical implementation, the influence of non-ideal parameters on the OSSR and RFSSR are analyzed.

A simplified optical millimeter-wave generation scheme based on frequency-quadrupling

This paper analyzes and demonstrates a simplified frequency quadrupling configuration for optical millimeter-wave (mm-wave) generation, in which the electrical phase shifter and optical filter are omitted. Theoretical analysis is given to reach the optimum operating conditions including direct current (DC) bias voltage, optical transmission point of the dual-parallel Mach-Zehnder modulator (MZM) bias voltage, optical transmission point of the dual-parallel Mach-Zehnder modulator (DP-MZM), amplitude of the radio frequency (RF) driving signal and the impact of the extinction ratio (EF) on the optical sideband suppression ratio (OSSR) and radio frequency spurious suppression ratio (RFSSR). Experiments prove an OSSR of 15 dB and an RFSSR of 26 dB for the new frequency quadrupling scheme at 6 GHz, 8GHz and 10 GHz of RF driving signal without any electrical phase shifter or optical filter. This system exhibits the advantage of low wavelength dependence and large frequency tunable range.

Optical Milli-Meter Wave Signal Generation using Frequency Octupling Without Optical Filter

In this paper, we show a practical technique to produce a great octupledfrequency optical Millimeter-Wave (MMW) signal utilizing two Mach-Zehnder modulators associated in course. A Continuous Wave (CW) Laser, two LiNb Mach-Zehnder Modulators(MZM) and a PIN Photodiode are utilized in the MMW signal age A careful change of Direct Current (DC) inclination, tweak index(MI) and the presentation of a 90° stage move between the 2 fell stages guarantees the age of recurrence octupled MMW signal.80 GHz RF signal is produced from a 10 GHz RF Local Oscillator (LO) with a most extreme reachable with Optical Sideband Suppression Ratio (OSSR) of 57 dB and a Radio Frequency Spurious Suppression Ratio (RFSSR) of beyond what 42 dB can be gotten. An optical bearer is tweaked, and unadulterated ±fourth-request sidebands are produced. The whole connection is reproduced utilizing Optisystem Software.

Performance Analysis of 80 GHz-Millimeter Wave Radio over Dispersive Fiber

Abstract The generation of 80 GHz millimeter wave (mm-wave) signal and its transmission over single mode fiber (SMF) is presented. The mm-wave signal is generated with dual parallel dual drive Mach Zehnder modulators using frequency quadrupling of 20 GHz radio frequency signal. Transmission of generated mm-wave signal over SMF has been investigated. The impact of varying modulation depth on optical side band suppression ratio and radio frequency spurious suppression ratio for different extinction ratios (ER) is studied. Further, the impact of dispersion, on received power is also analyzed. Error analysis between analytical and simulation results is carried out. It has been observed, that increasing ER leads to reduction in both peak error and mean error and the received power is reduced under the combined effect of second and third order dispersion at very high modulation depth.

Photonic generation of frequency 16-tupling Millimeter wave signal using polarization property without an optical filter

In this paper, a novel filter free method of generating 16 tupled millimeter wave signal using polarization property is proposed. Phase modulators utilized in this scheme are independent of bias voltage deviation and have higher extinction ratio thus ensuring higher quality of generated mm wave signal. A large frequency tunable range is achievable, as no optical filter is used. A 160 GHz microwave signal is obtained at the polarizer output when a 10GHz RF local oscillator is employed, which is 16 folds the RF drive signal. The simulation results show that the generated signal offers an Optical Sideband Suppression Ratio (OSSR) of 63dB and Radio Frequency Spurious Suppression Ratio (RFSSR) of 51dB. The sideband suppression ratios obtained in the proposed scheme is higher than the previously suggested schemes on microwave signal generation using polarization property. Theoretical computations validate the simulation results. Various parameters affecting system performance are analyzed in later sections.

INVESTIGATION OF DISPERSION ORDER ON CHIRP MICROWAVE GENERATION USING MICROWAVE PHOTONIC LINK WITHOUT OPTICAL FILTER

In this work, we investigate the influence of the second order-(2OD) and third order-(3OD) dispersion terms on chirp signal generation and transmission through RF photonic link without optical filter. Dispersion equations are formalised using Taylor series and Bessel function to study the link performance. Our result (Eye diagrams) shows that the 2OD+3OD have significant impact on chirp mm-wave propagating through fiber of different lengths. In this paper chirp mm signal is controlled at photo detector by individual phase term of external modulators. Moreover, we also demonstrated experimentally that the chirp rate can be significantly controlled by properly choosing the type of fiber in the experiments. We discussed the RF photonic link performance in terms of Optical Sideband Suppression Ratio (OPSSR), Radio Frequency Spurious Suppression Ratio (RFSSR), Bit Error Rate (BER). Theoretical results are verified using MATLAB Software.