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This paper presents the design, fabrication, and test results for a novel waveguide multimode directional coupler (MDC). The coupler fabricated from dissimilar frequency band waveguides, is capable of isolating power at the 2nd harmonic frequency from the fundamental power at the output port of traveling-wave tube amplifiers. Test results from proof-of-concept demonstrations are presented for Ku/Ka-band...
In this paper, we present a differential magnetless circulator by combining two angular-momentum-biased single-ended circulators, each of which consists of three first-order bandstop LC filters connected in a delta topology and modulated in time with a phase difference of 120 deg between each other. Compared to a single-ended architecture, the differential one drastically reduces even-order intermodulation...
This paper reports on an internal study carried out at the European Space Agency (ESA) for assessing the reference performance of Payload Data Transmitters achieved in the mid-term. This assessment is meant to provide input to the ESA roadmaps for the 2023 time frame. The assessment is carried out for various space missions, from low Earth to deep space orbits. Taking advantage of technology evolution...
Deep-space missions present unique demands on spacecraft components. These include typically stringent size, weight, and power specifications, and designs must also often adhere to strict requirements for radiation, long mission life, and reliability. For flight RF/microwave systems, this translates in particular to design constraints on antennas, radios, and power amplifiers and how these systems...
The telecommunications systems for two NASA deep-space missions to Jupiter's moon Europa are presented. One mission, Europa Clipper, is a Jovian orbiter with multiple Europa flybys; the other mission, Europa Lander, includes a Carrier and Relay Spacecraft (CRS), Deorbit Stage, Descent Stage (DS), and a Lander. Both missions are designed to communicate to Earth via the NASA Deep Space Network (DSN)...
In meeting the needs of a number of different missions, JHU/APL's Space Exploration Sector RF Engineering Group has produced a family of high-reliability, extremely low size, weight, and power (SWaP) software-defined radio (SDR) products for near and deep space applications called Frontier Radio (FR) [1]. With flight heritage on multiple successful missions, the latest flight version includes a Ka-band...
An artificial gradient-index lens for phase correction of a horn antenna in the Ka-band is presented. By introducing a gradient of the geometric features in the single layer fishnet unit cell, a phase variation between −180 and +180 degress can be obtained. The relation between the geometric dimensions, phase- and amplitude distribution is presented. Furthermore, phase-correction and resulting improved...
In this paper, the distinction between Zenneck waves and surface plasmon polaritons is illustrated. Both are evanescent waves. The surface plasmon needs to be excited by an electron beam which can be effectively generated by a source of electrons or a quasiparticle like an evanescent wave which can tunnel through the medium and thus excite the electrons. This electron wave produces its own electromagnetic...
In this paper, Discrete Dipole Approximation (DDA) is presented as a simulation tool for predicting the electromagnetic properties of one dimensional metasurface antennas and slotted waveguide antennas. The proposed method is verified by demonstrating excellent agreement between DDA predictions and that of a full-wave electromagnetic solver. This technique is especially attractive since it allows...
A two-dimensional (2D) periodic leaky-wave antenna consisting of a periodic distribution of rectangular patches on a grounded dielectric substrate, excited by a narrow slot in the ground plane, is studied here. The TM0 surface wave that is normally supported by a grounded dielectric substrate is perturbed by the presence of the periodic patches to produce radially-propagating leaky waves. In addition...
In this paper, an ultra-wideband (UWB) Wilkinson power divider with ultra-narrow dual-notched bands is proposed. The multi-mode UWB characteristic is achieved using stepped-impedance open-circuited stub (SIOS) and broadside-coupled microstrip/CPW (BCMC) transition. Then, to cancel the interferences from existed wireless local-area network (WLAN) signals (i.e., 5.2 and 5.8 GHz), two pairs of embedded...
A 6-way planar ring for combining/dividing signals is presented in this paper. Conventional planar power combining/dividing structures use derivatives of the Wilkinson combiner in a ladder like structure, or radial combiners. The ring combiner can be made smaller, provide higher port isolation, improved harmonic suppression and a single isolation port (e.g., delta output port), allowing energy harvesting...
A novel microstrip Wilkinson power divider with separate paths for the even and odd modes is presented in this paper. The proposed divider has a single quarter wavelength impedance transformer section and a reduced dimension in the transverse direction. This is achieved by etching a longitudinal slot in the ground plane of the microstrip where the isolation resistor is added. To develop a design procedure...
In this paper, a design method of an ultra-wideband multi-section power divider on suspended stripline (SSL) is presented. A clear design guideline for ultra-wideband power dividers is provided. As a design example, a 10-section SSL power divider is implemented. The fabricated divider exhibits the minimum insertion loss of 0.3 dB, the maximum insertion loss of 1.5 dB from 1 to 19 GHz. The measured...
We demonstrate the first silicon photonics enabled hyper-wideband wireless link with an instantaneous bandwidth of 12 GHz, which is 85% of the center frequency of 14 GHz. The silicon photonics based RF receiver consists of a four-channel optical phase encoder, an integrated hybrid-silicon mode-locked laser, and two silicon ring notch filters. The received CDMA RF wireless signal is correlated to baseband...
We present a novel photoconductive terahertz emitter, which offers significantly high terahertz radiation power levels through three-dimensional light confinement near terahertz radiating elements. Arrays of plasmonic nano-antennas fabricated on a photo-absorbing semiconductor substrate are used as the terahertz radiating elements. The plasmonic nano-antenna arrays are designed to offer high radiation...
In this paper, a linear driver for optical modulators in a 0.13 μm SiGe:C BiCMOS technology with fT/fmax of 300/500 GHz is presented. The driver is implemented following a distributed amplifier topology in a differential manner. In a 50-Ω environment, the circuit delivers a maximum differential output amplitude of 4 Vpp, featuring a small-signal gain of 13 dB and 3-dB bandwidth of 90 GHz. Time-domain...
An optical ring resonator (ORR) based integrated optical beamforming network (OBFN) for a W-band millimeter wave phased array antenna is reported. The delay response of a 3-ORR delay line is optimized and dynamic tuning ranges of 208.7 ps and 172.4 ps for the true time delay bandwidths of 6.3 GHz and 8.7 GHz are achieved. Moreover, all of the delay paths are successfully tuned with 4. 2 ps delay difference...
A 2.4GHz-band high power and high efficiency injection-locked oscillator has been developed for use in the microwave ovens having uniform heating as well as subtle temperature control. With the use of the imbalanced coupling resonator in the feedback circuit, an output power of 210W and an efficiency of 51% have been successfully obtained at 2.45GHz, where a reference signal of less than 1/10,000...
An injection-locked magnetron was investigated at low power injection. The 1 kW magnetron has been locked over the ratio of the input power to output power of −57 dB. It is much less than the required injection power in previous experiments. The purity of spectrum was presented. The phase noise of the locked magnetron was less than −93.1 dBc/Hz at 10 kHz offset. The oscillation spectrum has FM noise...
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