Low-Power, High-Speed Transceivers for Network-on-Chip Communication

Networks on chips (NoCs) are becoming popular as they provide a solution for the interconnection problems on large integrated circuits (ICs). But even in a NoC, link-power can become unacceptably high and data rates are limited when conventional data transceivers are used. In this paper, we present a low-power, high-speed source-synchronous link transceiver which enables a factor 3.3 reduction in link power together with an 80% increase in data-rate. A low-swing capacitive pre-emphasis transmitter in combination with a double-tail sense-amplifier enable speeds in excess of 9 Gb/s over a 2 mm twisted differential interconnect, while consuming only 130 fJ/transition without the need for an additional supply. Multiple transceivers can be connected back-to-back to create a source-synchronous transceiver-chain with a wave-pipelined clock, operating with 6sigma offset reliability at 5 Gb/s

Dynamic Optical Networks for Data Centres and Media Production

This thesis explores all-optical networks for data centres, with a particular focus on network designs for live media production. A design for an all-optical data centre network is presented, with experimental verification of the feasibility of the network data plane. The design uses fast tunable (< 200 ns) lasers and coherent receivers across a passive optical star coupler core, forming a network capable of reaching over 1000 nodes. Experimental transmission of 25 Gb/s data across the network core, with combined wavelength switching and time division multiplexing (WS-TDM), is demonstrated. Enhancements to laser tuning time via current pre-emphasis are discussed, including experimental demonstration of fast wavelength switching (< 35 ns) of a single laser between all combinations of 96 wavelengths spaced at 50 GHz over a range wider than the optical C-band. Methods of increasing the overall network throughput by using a higher complexity modulation format are also described, along with designs for line codes to enable pulse amplitude modulation across the WS-TDM network core. The construction of an optical star coupler network core is investigated, by evaluating methods of constructing large star couplers from smaller optical coupler components. By using optical circuit switches to rearrange star coupler connectivity, the network can be partitioned, creating independent reserves of bandwidth and resulting in increased overall network throughput. Several topologies for constructing a star from optical couplers are compared, and algorithms for optimum construction methods are presented. All of the designs target strict criteria for the flexible and dynamic creation of multicast groups, which will enable future live media production workflows in data centres. The data throughput performance of the network designs is simulated under synthetic and practical media production traffic scenarios, showing improved throughput when reconfigurable star couplers are used compared to a single large star. An energy consumption evaluation shows reduced network power consumption compared to incumbent and other proposed data centre network technologies

A Recofigurable Tri-Band Interconnect for Future Network-On-Chip

The scaling of CMOS feature sizes has yielded the capability of integrating heterogeneous intellectual properties (IPs) like graphics processing units (GPUs), digital signal processors (DSPs) and central processing units (CPUs) on a single die. The collection of multiple IPs on a single die presents a problem of reliable communication due to congestion. The infrastructure that facilitates and manages communication among IPs is referred to as a network-on-chip (NoC). Its ultimate goal should be low latency with negligible power and area consumption. Unfortunately, as CMOS feature sizes have been scaling smaller, this has exacerbated latency and signal degradation due to increasing on-chip channel resistance. Furthermore, contemporary interfaces use baseband-only signaling and have critical limitations like exponential energy consumption, limited bandwidth and non-reconfigurable data access.;In this work, we propose an energy efficient tri-band (baseband + 2 RF bands) signaling interface that is capable of simultaneous bi-directional communication and reconfigurable data access. Additionally, communication is accomplished through a shared transmission line which reduces the overall number of global interconnections. As a result, this reduces area consumption and mitigates interconnection complexity. The primary signicance of this interconnect configuration compared to contemporary designs is an increase of bandwidth and energy efficiency.;The interconnect design is composed of a baseband transceiver and two RF (10Ghz and 20GHz) transceivers. The RF transceivers utilize amplitude-shift keying (ASK) modulation scheme. ASK modulation allows ease of circuit design, but most importantly it can be used for noncoherent communication, which we implemented in this system. Noncoherent ASK modulation is area conservative and power efficient since there is no longer a need for power-hungry frequency synthesizers. Moreover, noncoherent ASK demodulation accomplishes direct-down conversation through a passive self-mixer for additional power savings.;The results from our work show that a multi-band interconnect is a suitable remedy for future NoC communication that has been reaching its bandwidth limitation with baseband-only signaling. In conclusion, this work demonstrates a sustainable balance of energy efficiency and increased bandwidth for future on-chip interconnect designs

Design of Low-Power NRZ/PAM-4 Wireline Transmitters

Rapid growing demand for instant multimedia access in a myriad of digital devices has pushed the need for higher bandwidth in modern communication hardwares ranging from short-reach (SR) memory/storage interfaces to long-reach (LR) data center Ethernets. At the same time, comprehensive design optimization of link system that meets the energy-efficiency is required for mobile computing and low operational cost at datacenters. This doctoral study consists of design of two low-swing wireline transmitters featuring a low-power clock distribution and 2-tap equalization in energy-efficient manners up to 20-Gb/s operation. In spite of the reduced signaling power in the voltage-mode (VM) transmit driver, the presence of the segment selection logic still diminishes the power saving benefit. The first work presents a scalable VM transmitter which offers low static power dissipation and adopts an impedance-modulated 2-tap equalizer with analog tap control, thereby obviating driver segmentation and reducing pre-driver complexity and dynamic power. Per-channel quadrature clock generation with injection-locked oscillators (ILO) allows the generation of rail-to-rail quadrature clocks. Energy efficiency is further improved with capacitively driven low-swing global clock distribution and supply scaling at lower data rates, while output eye quality is maintained at low voltages with automatic phase calibration of the local ILO-generated quarter-rate clocks. A prototype fabricated in a general purpose 65 nm CMOS process includes a 2 mm global clock distribution network and two transmitters that support an output swing range of 100-300mV with up to 12-dB of equalization. The transmitters achieve 8-16 Gb/s operation at 0.65-1.05 pJ/b energy efficiency. The second work involves a dual-mode NRZ/PAM-4 differential low-swing voltage-mode (VM) transmitter. The pulse-selected output multiplexing allows reduction of power supply and deterministic jitter caused by large on-chip parasitic inherent in the transmission-gate-based multiplexers in the earlier work. Analog impedance control replica circuits running in the background produce gate-biasing voltages that control the peaking ratio for 2-tap feed-forward equalization and PAM-4 symbol levels for high-linearity. This analog control also allows for efficient generation of the middle levels in PAM-4 operation with good linearity quantified by level separation mismatch ratio of 95%. In NRZ mode, 2-tap feedforward equalization is configurable in high-performance controlled-impedance or energy-efficient impedance-modulated settings to provide performance scalability. Analytic design consideration on dynamic power, data-rate, mismatch, and output swing brings optimal performance metric on the given technology node. The proof-of-concept prototype is verified on silicon with 65 nm CMOS process with improved performance in speed and energy-efficiency owing to double-stack NMOS transistors in the output stage. The transmitter consumes as low as 29.6mW in 20-Gb/s NRZ and 25.5mW in the 28-Gb/s PAM-4 operations

Wavelength tunable transmitters for future reconfigurable agile optical networks

Wavelength tuneable transmission is a requirement for future reconfigurable agile optical networks as it enables cost efficient bandwidth distribution and a greater degree of transparency. This thesis focuses on the development and characterisation of wavelength tuneable transmitters for the core, metro and access based WDM networks. The wavelength tuneable RZ transmitter is a fundamental component for the core network as the RZ coding scheme is favoured over the conventional NRZ format as the line rate increases. The combination of a widely tuneable SG DBR laser and an EAM is a propitious technique employed to generate wavelength tuneable pulses at high repetition rates (40 GHz). As the EAM is inherently wavelength dependant an accurate characterisation of the generated pulses is carried out using the linear spectrogram measurement technique. Performance issues associated with the transmitter are investigated by employing the generated pulses in a 1500 km 42.7 Gb/s circulating loop system. It is demonstrated that non-optimisation of the EAM drive conditions at each operating wavelength can lead to a 33 % degradation in system performance. To achieve consistent operation over a wide waveband the drive conditions of the EAM must be altered at each operating wavelength. The metro network spans relatively small distances in comparison to the core and therefore must utilise more cost efficient solutions to transmit data, while also maintaining high reconfigurable functionality. Due to the shorter transmission distances, directly modulated sources can be utilised, as less precise wavelength and chirp control can be tolerated. Therefore a gain-switched FP laser provides an ideal source for wavelength tuneable pulse generation at high data rates (10 Gb/s). A self-seeding scheme that generates single mode pulses with high SMSR (> 30 dB) and small pulse duration is demonstrated. A FBG with a very large group delay disperses the generated pulses and subsequently uses this CW like signal to re-inject the laser diode negating the need to tune the repetition rate for optimum gain-switching operation. The access network provides the last communication link between the customer’s premises and the first switching node in the network. FTTH systems should take advantage of directly modulated sources; therefore the direct modulation of a SG DBR tuneable laser is investigated. Although a directly modulated TL is ideal for reconfigurable access based networks, the modulation itself leads to a drift in operating frequency which may result in cross channel interference in a WDM network. This effect is investigated and also a possible solution to compensate the frequency drift through simultaneous modulation of the lasers phase section is examined

Design of High-Speed Power-Efficient Transmitter with Time-Based Equalization

본 논문은 고속, 저전력으로 동작하는 유선 송신기의 설계에 대해 설명하고 있다. 분리되지 않은 출력 드라이버가 있는 에너지 효율적인 전압 모드 송신기는 위상 지연 분석을 기반으로 시간 영역에서 채널 손실을 보상한다. 직렬화된 데이터 스트림이 아닌 송신 클럭의 위상을 변조함으로써 제안된 송신기는 데이터 의존적 지터를 크게 줄인다. 수평 아이 오프닝은 전송된 데이터의 실행 길이에 따라 제로 크로싱 시간 변동을 보상함으로써 개선된다. 제안된 방식은 큰 신호 및 스위칭 전력을 소비하는 많은 드라이버 슬라이스를 제거함으로써 드라이버 복잡성을 크게 줄인다. 프로토타입 칩은 28 nm CMOS 공정으로 제작되었으며 0.045 mm2 의 실제 면적을 차지한다. 측정된 결과는 제안된 송신기가 1.0 V 공급에서 440 mVppd의 출력 스윙으로 22 Gb/s의 속도에서 0.95 pJ/b의 에너지 효율을 달성함을 보여준다. 또한 피크 대 피크 지터는 15.0 dB 손실의 채널에 대해 제안된 위상 지연 보상을 통해 22 Gb/s의 속도에서 34 ps에서 20 ps로 감소된다.In this thesis, a design of high-speed, power-efficient wireline transmitter is reported. An energy-efficient voltage-mode transmitter with an un-segmented output driver equalizes channel loss in the time-domain based on the phase de-lay analysis. By modulating the phase of the transmitting clock rather than the serialized data stream, the proposed transmitter significantly reduces the data-dependent jitter. The horizontal eye-opening is improved by compensating for the zero-crossing time variation dependent on the run-length of the transmitted data. The proposed scheme significantly reduces the driver complexity by elim-inating many driver slices that consume significant signaling and switching power. The prototype chip has been fabricated in a 28-nm CMOS process and occupies an active area of 0.045 mm2. The measured results show that the pro-posed transmitter achieves an energy efficiency of 0.95 pJ/b at 22 Gb/s with an output swing of 440 mVppd at 1.0 V supply. In addition, peak-to-peak jitter is reduced from 34 ps to 20 ps at 22 Gb/s with the proposed phase delay compen-sation over the channel with a 15.0 dB loss.CHAPTER 1 INTRODUCTION 1 1.1 MOTIVATION 1 1.2 THESIS ORGANIZATION 4 CHAPTER 2 BACKGROUNDS 5 2.1 OVERVIEW 5 2.2 FEED-FORWARD EQUALIZATION 7 2.2.1 AMPLITUDE-DOMAIN EQUALIZATION 7 2.2.2 PHASE-DOMAIN EQUALIZATION 12 2.2.3 PULSE-WIDTH MODULATION 18 2.3 ADAPTIVE FEED-FORWARD EQUALIZATION 21 2.3.1 AMPLITUDE-DOMAIN EQUALIZATION 21 2.3.2 PULSE-WIDTH MODULATION 24 CHAPTER 3 DESIGN OF THE TIME-BASED FEED-FORWARD EQUALIZATION OF THE TRANSMITTER 26 3.1 OVERVIEW 26 3.2 BASIC CONCEPT OF TIME-BASED FFE 28 3.2.1 ZERO-CROSSING TIME 28 3.2.2 PHASE DELAY 32 3.2.3 FINDING THE OPTIMUM COEFFICIENT 39 3.2.4 COMPARISON WITH CONVENTIONAL FFE 43 3.3 ADAPTIVE TIME-BASED FFE 50 3.3.1 OVERVIEW 50 3.3.2 BEHAVIORAL MODELING 51 3.3.3 SIMULATION RESULTS 53 3.4 TRANSMITTER IMPLEMENTATION 60 3.4.1 OVERVIEW 60 3.4.2 PHASE MODULATION 62 3.4.3 SERIALIZER AND CLOCK PATH 67 CHAPTER 4 MEASUREMENT 71 4.1 OVERVIEW 71 4.2 EYE DIAGRAM 76 4.3 POWER CONSUMPTION 81 CHAPTER 5 CONCLUSION 84 BIBLIOGRAPHY 86 초 록 92박

Efficient and Wideband Load Modulated Power Amplifiers for Wireless Communication

The increasing demand for mobile data traffic has resulted in new challenges and requirements for the development of the wireless communication infrastructure. With the transition to higher frequencies and multi-antenna systems, radio frequency (RF) hardware performance, especially the power amplifier (PA), becomes increasingly important. Enhancing PA energy efficiency and bandwidth is vital for maximizing channel capacity, reducing operational costs, and facilitating integration.In the first part of the thesis, the bandwidth limitations of the standard two-way Doherty PA are discussed. A comprehensive analysis is provided, and the frequency responses of different Doherty combiner networks are presented. Furthermore, a Doherty combiner network is proposed, notable for its inherent broadband frequency and its capacity to account for the influence of output parasitics and packaged components from the active devices. The introduced Doherty combiner network is experimentally verified by a wideband gallium nitride (GaN) Doherty PA operating over 1.6-2.7 GHz.In the second part of the thesis, an analytically based combiner synthesis approach for the three-stage Doherty PA is proposed and presented. A compact output combiner network, together with the input phase delays, is derived directly from transistor load-pull data and the PA design requirements. The technique opens up new design space for three-stage Doherty PAs with reconfigurable high-efficiency power back-off levels. The utility of the proposed technique is demonstrated by the implementation of a 30-W GaN three-stage Doherty PA prototype at 2.14 GHz. Measurements show that a drain efficiency of 68% and 55% is exhibited at 6- and 10-dB back-off power, respectively.In the third part, a new PA architecture named the circulator load modulated amplifier (CLMA), is proposed. This architecture utilizes active load modulation for achieving enhanced back-off efficiency. Two active devices are incorporated in this innovative architecture, and a non-reciprocal circulator-based combiner is leveraged. Following this, the sequential CLMA (SCLMA) is introduced, characterized by its ability to enhance back-off efficiency without the necessity of load modulation. GaN demonstrator circuits for both CLMA and SCLMA architectures, whether with dual-input or RF single-input, are designed and fabricated, with excellent performance being measured.\ua0The thesis contributes novel design techniques and architectures to enhance PA efficiency and bandwidth. These findings pave the way for energy-efficient and adaptable RF transmitters in future wireless communication systems

Design of communication systems based on broadband sources for fiber and free space optical links

[ES] Las comunicaciones ópticas inalámbricas (OWC) constituyen una tecnología muy prometedora para el desarrollo de futuras comunicaciones inalámbricas. De hecho, ha despertado un interés creciente entre los investigadores y varias empresas de todo el mundo trabajan actualmente en el desarrollo de redes inalámbricas de muy alta velocidad. Las comunidades científica e industrial consideran la OWC como una tecnología complementaria en sus diversas formas: comunicaciones ópticas en el espacio libre (FSO), comunicaciones de luz visible (VLC) o fidelidad de la luz (Li-Fi). El espectro óptico ha sido considerado durante muchos años como una gran oportunidad para las comunicaciones inalámbricas, especialmente debido a la saturación del espectro de radiofrecuencia (RF). Esta disertación trata del uso de fuentes de banda ancha en sistemas de transmisión de luz visible (VLC), así como en sistemas de transmisión en el espectro infrarrojo por fibra óptica. En el trabajo de investigación realizado se pueden distinguir tres partes: En la primera parte, se considera el estudio y la simulación de componentes de Diodos Emisores de Luz (LED) con el software WIEN2k centrándose en las propiedades ópticas y eléctricas de los elementos II-VI. La segunda parte trata del diseño, la implementación y las pruebas de diferentes prototipos de comunicación VLC para la transmisión analógica y digital en modo simplex y semidúplex. Hemos demostrado un sistema OWC empleando una fuente de banda ancha (LED) para la transmisión no sólo de datos, sino también para la transmisión inalámbrica de energía. Además, se aborda el problema de la sincronización y la detección del nivel "1" o "0" de un bit en los sistemas de comunicación inalámbrica óptica implementados que surge como consecuencia de la atenuación de la luz a lo largo de la distancia y al problema de la pérdida de línea de visión (NLOS) entre el emisor y el receptor. Para hacer frente a este problema, se ha proporcionado un protocolo de comunicación que garantiza la transmisión fiable de datos digitales con un algoritmo de detección de nivel de bits adaptativo y se ha demostrado su eficacia mediante la transmisión de textos e imágenes. Además, esta tesis aporta una solución para la implementación de transmisores multiplexados en redes con división de longitud de onda (WDM) para formatos de modulación con multiplexación por división de frecuencia ortogonal (OFDM) basados en el uso de fuentes de banda ancha en el espectro infrarrojo para redes de fibra bidireccionales centralizadas. A pesar de las limitaciones impuestas por la dispersión cromática en el uso de este tipo de fuentes ópticas, la inclusión de ciertas estructuras antes de la detección permite la transmisión de señales OFDM en enlaces ópticos. En este trabajo se ha demostrado experimentalmente la reutilización de portadoras, la asignación dinámica de ancho de banda y la transmisión de señales OFDM multibanda mediante el uso de fuentes ópticas de banda ancha en redes WDM. Los principales resultados obtenidos en cada parte de esta tesis doctoral muestran los procedimientos de estudio, la eficacia de las soluciones propuestas y las limitaciones encontradas.[CA] Les comunicacions òptiques sense fils (OWC) constitueixen una tecnologia molt prometedora per al desenvolupament de futures comunicacions sense fils. De fet, ha despertat un interés creixent entre els investigadors i diverses empreses de tot el món treballen actualment en el desenvolupament de xarxes sense fils de molt alta velocitat. Les comunitats científica i industrial consideren la OWC com una tecnologia complementària en les seues diverses formes: comunicacions òptiques en l'espai lliure (FSO), comunicacions de llum visible (VLC) o fidelitat de la llum (Li-Fi). L'espectre òptic ha sigut considerat durant molts anys com una gran oportunitat per a les comunicacions sense fils, especialment a causa de la saturació de l'espectre de radiofreqüència (RF). Aquesta dissertació tracta de l'ús de fonts de banda ampla en sistemes de transmissió de llum visible (VLC), així com en sistemes de transmissió en l'espectre infraroig per fibra òptica. En el treball de recerca realitzat es poden distingir tres parts: ¿ En la primera part, es considera l'estudi i la simulació de components de Díodes Emissors de Llum (LED) amb el software WIEN2k centrant-se en les propietats òptiques i elèctriques dels elements II-VI. ¿ La segona part tracta del disseny, la implementació i les proves de diferents prototips de comunicació VLC per a la transmissió analògica i digital de manera simplex i semidúplex. Hem demostrat un sistema OWC emprant una font de banda ampla (LED) per a la transmissió no sols de dades, sinó també per a la transmissió sense fil d'energia. A més, s'aborda el problema de la sincronització i la detecció del nivell "1" o "0" d'un bit en els sistemes de comunicació sense fil òptica implementats, que sorgeix a conseqüència de l'atenuació de la llum al llarg de la distància i al problema de la pèrdua de línia de visió (NLOS) entre l'emissor i el receptor. Per a fer front a aquest problema, s'ha proporcionat un protocol de comunicació que garanteix la transmissió fiable de dades digitals amb un algorisme de detecció de nivell de bits adaptatiu i s'ha demostrat la seua eficàcia mitjançant la transmissió de textos i imatges. ¿ A més, aquesta tesi aporta una solució per a la implementació de transmissors multiplexats en xarxes amb divisió de longitud d'ona (WDM) per a formats de modulació amb multiplexació per divisió de freqüència ortogonal (OFDM) basats en l'ús de fonts de banda ampla en l'espectre infraroig per a xarxes de fibra bidireccionals centralitzades. Malgrat les limitacions imposades per la dispersió cromàtica en l'ús d'aquest tipus de fonts òptiques, la inclusió d'unes certes estructures abans de la detecció permet la transmissió de senyals OFDM en enllaços òptics. En aquest treball s'ha demostrat experimentalment la reutilització de portadores, l'assignació dinàmica d'amplada de banda i la transmissió de senyals OFDM multibanda mitjançant l'ús de fonts òptiques de banda ampla en xarxes WDM. Els principals resultats obtinguts en cada part d'aquesta tesi doctoral mostren els procediments d'estudi, l'eficàcia de les solucions proposades i les limitacions trobades.[EN] Optical wireless communication (OWC) is a very promising technology for future wireless communications developments. It has attracted increasing interest from researchers and several companies around the world are currently working on the development of very high-speed wireless networks. The scientific and industrial communities believe that OWC will be a complementary technology in its various forms: Free Space Optical communications (FSO), Visible Light Communications (VLC), Light Fidelity (Li-Fi). In fact, the optical spectrum has been considered for many years as a great opportunity for wireless communications especially due to the saturation of the radio frequency (RF) spectrum. This dissertation deals with the use of broadband sources in visible light transmission systems (VLC) as well as fiber optic systems. To carry out the research, three parts can be distinguished: In the first part, we consider the study and simulation of Light Emitting Diode (LED) components with the WIEN2k software by focusing on the optical and electrical properties of elements II-VI. The second part deals with the design, implementation and testing of different VLC communication prototypes for analog and digital transmission in simplex and half-duplex mode. We have demonstrated that an OWC system using a broadband source (i.e. an LED) can be used not only for data transmission, but also for wireless power transmission. Moreover, the synchronization problem and the detection of level "1" or "0" of a bit often arise in the optical wireless communication systems. This is a result of the attenuation nature of the light over the distance and the problem of Non Line-Of-Sight (NLOS) between the emitter and the receiver. To deal with this problem, a communication protocol ensuring reliable digital data transmission with an adaptive bit level detection algorithm has been provided and its effectiveness has been demonstrated by the transmission of texts and images. In addition, this thesis provides a solution for the implementation of wavelength division multiplexed - orthogonal frequency division multiplexed (WDM-OFDM) transmitters based on the use of broadband sources in the infrared spectrum for centralized bidirectional fiber networks. Despite the chromatic dispersion that avoids the use of this type of optical sources, the inclusion of certain structures before detection allows the transmission of OFDM signals in optical links. Carrier reuse, dynamic bandwidth allocation and multiband OFDM signals transmission will be experimentally demonstrated by using optical broadband sources in WDM networks. The main results obtained during this thesis work demonstrate the study procedures, for each part, the effectiveness of the proposed solutions as well as the constraints encountered.Sekkiou, I. (2021). Design of communication systems based on broadband sources for fiber and free space optical links [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/172542TESI

Modeling of Photonic Devices and Photonic Integrated Circuits for Optical Interconnect and RF Photonic Front-End Applications

Photonic integrated circuits (PICs) offer compelling solutions for applications in many areas due to the sufficient functionality and excellent performance. Optical interconnects and radio frequency (RF) photonics are two areas in which PICs have potential to be widely used. Optical interconnect system efficiency is dependent on the ability to optimize the transceiver circuitry for low-power and high-bandwidth operation, motivating co-simulation environments with compact optical device simulation models. Compact models for vertical-cavity surface-emitting lasers (VCSELs) and silicon carrier-injection/depletion ring modulators which include both non-linear electrical and optical dynamics are presented, and excellent matching between co-simulated and measured optical eye diagrams is achieved. Advanced modulation schemes, such as four-level pulse-amplitude modulation (PAM4), are currently under consideration in both high-speed electrical and optical interconnect systems. How NRZ and PAM4 modulation impacts the energy efficiency of an optical link architecture based on silicon photonic microring resonator modulators and drop filters is analyzed. Two ring modulator device structures are proposed for PAM4 modulation, including a single-segment device driven with a multi-level PAM4 transmitter and a two-segment device driven by two simple NRZ (MSB/LSB) transmitters. Modeling results show that the PAM4 architectures achieve superior energy efficiency at higher data rates due to the relaxed circuit bandwidth. While RF photonics offer the promise of chip-scale opto-electrical systems with high levels of functionality, in order to avoid long and unsuccessful design cycles, efficient models that allow for co-simulation are necessary. In order to address this, an optical element modeling framework is proposed based on Verilog-A which allows for the co-simulation of optical elements with transistor-level circuits in a Cadence design environment. Three components in the RF photonic system, Mach Zehnder (MZ) modulators, 4th order all pass filter (APF)-based optical filters, and jammer-suppression notch filters are presented to demonstrate the capability of efficient system design in co-simulation environments