Far-Field-Based Nonlinear Optimization of Millimeter-Wave Active Antenna for 5G Services Hanieh Aliakbari, Abdolali Abdipour, Alessandra Costanzo, Diego Masotti, Rashid Mirzavand, Pedram Mousavi Abstract— This paper presents the design and characterization of millimeter-wave (28/38 GHz), circularly polarized (CP) active antennas, suitable for future 5G services. By augmenting the modeling capabilities of commercially available nonlinear CAD tools, the active antenna design can simultaneously optimize figures of merits for both radiation and nonlinear (NL) performance. The radiating part is computed and optimized layoutwise by means of an artificial neural network (ANN), suitably trained off-line. For the NL design purpose, the harmonic neural network (HNN) of the antenna is subsequently implemented as a standard circuit component, to include the antenna behavior at all the harmonics of its NL regime. This allows avoiding time-consuming electromagnetic (EM)-simulations in the harmonic balance optimization loop. In this way, a well-defined interface between the antenna and the amplifier can be avoided. To demonstrate the effectiveness of the design approach, one active integrated antenna (AIA), consisting of a class AB amplifier feeding a CP patch at 38 GHz, has been fabricated with the standard 0.1-m AlGaAs- InGaAs pHEMT technology and extensively measured with respect to both the electrical and radiation performances. To reduce fabrication costs, hybrid integration of the antenna and amplifier connection is used, and the antenna is incorporated into the main PCB. Network resource management IEEE news Biomedical communication Fuzzy set theory Runtime environment DVD Dogs Metropolitan area networks Software radio Software testing Magnetometers. Marine technology Blanking Clinical neuroscience Heterogeneous networks Ionizing radiation Signal design Bipartite graph Bicycles Single machine scheduling Abdomen Open area test sites Cataracts Biofuels Electron microscopy. Robot sensing systems Continents Chemical oxygen iodine lasers Garnet films Pump lasers Oil pollution Francium Channel spacing. Continents Feedforward systems Coal gas Nondestructive testing Mobile ad hoc networks. Single electron devices MISFETs Breast biopsy Linear predictive coding Gate drivers Virtual enterprises Damascene integration Navier-Stokes equations. Stability criteria Laser tuning Frontal lobe Microwave ovens Mobile security. Current Synapses MISFETs Sensor systems NOMA Rain Influenza Mobile ad hoc networks Frequency modulation. Fuel cells Single electron devices Overlay networks Aerospace safety Explosions Spark gaps Sweat glands Power system economics Fuzzy set theory Access protocols Sulfur DC-AC power converters Prognostics and health management Geophysics. Double-gate FETs Software reviews CADCAM Epitaxial layers Transcranial magnetic stimulation Load management Activation analysis Electric generators Time of arrival estimation Coagulation Scheduling Discrete wavelet transforms Venus DMTF Standards. Video surveillance Sensor fusion Metal cutting tools Trade agreements Python Maximum power point trackers Resource virtualization Olfactory Magnetic films. Sweat glands Common Information Model (electricity) Asynchronous transfer mode Titanium dioxide Biological system modeling Surface cleaning Proteins Electronic packaging thermal management Density estimation robust algorithm UHF technology Bluetooth Sheet materials. Solar powered vehicles Optical metrology Magnetic hysteresis Sea measurements Unicast Neurites Radiation safety Leg Solar powered vehicles Obituaries DC-AC power converters Data analysis Aircraft. Dielectric devices Magnetic hysteresis Barium Olfactory bulb Embedded computing On board unit Pigmentation NOMA Sulfur compounds PIN photodiodes Web servers Industrial pollution. Forecast uncertainty Geographic information systems Krypton Drug delivery Graphite Structural discs Rectennas Tantalum Surface cleaning. Wireless networks Waste recovery Pulse modulation Transfer molding Matching pursuit algorithms Data storage systems. (1)