Multi-frequency Data Parallel Spin Wave Logic Gates

By their very nature, Spin Waves (SWs) with different frequencies can propagate through the same waveguide without affecting each other, while only interfering with their own species. Therefore, more SW encoded data sets can coexist, propagate, and interact in parallel, which opens the road towards hardware replication free parallel data processing. In this paper, we take advantage of these features and propose a novel data parallel spin wave based computing approach. To explain and validate the proposed concept, byte-wide 2-input XOR and 3-input Majority gates are implemented and validated by means of Object Oriented MicroMagnetic Framework (OOMMF) simulations. Furthermore, we introduce an optimization algorithm meant to minimize the area overhead associated with multifrequency operation and demonstrate that it diminishes the byte-wide gate area by 30% and 41% for XOR and Majority implementations, respectively. To get inside on the practical implications of our proposal we compare the byte-wide gates with conventional functionally equivalent scalar SW gate based implementations in terms of area, delay, and power consumption. Our results indicate that the area optimized 8-bit 2-input XOR and 3-input Majority gates require 4.47x and 4.16x less area, respectively, at the expense of 5% and 7% delay increase, respectively, without inducing any power consumption overhead. Finally, we discuss factors that are limiting the currently achievable parallelism to 8 for phase based gate output detection and demonstrate by means of OOMMF simulations that this can be increased 16 for threshold based detection based gates.

Multi-frequency Data Parallel Spin Wave Logic Gates

By their very nature, Spin Waves (SWs) with different frequencies can propagate through the same waveguide without affecting each other, while only interfering with their own species. Therefore, more SW encoded data sets can coexist, propagate, and interact in parallel, which opens the road towards hardware replication free parallel data processing. In this paper, we take advantage of these features and propose a novel data parallel spin wave based computing approach. To explain and validate the proposed concept, byte-wide 2-input XOR and 3-input Majority gates are implemented and validated by means of Object Oriented MicroMagnetic Framework (OOMMF) simulations. Furthermore, we introduce an optimization algorithm meant to minimize the area overhead associated with multifrequency operation and demonstrate that it diminishes the byte-wide gate area by 30% and 41% for XOR and Majority implementations, respectively. To get inside on the practical implications of our proposal we compare the byte-wide gates with conventional functionally equivalent scalar SW gate based implementations in terms of area, delay, and power consumption. Our results indicate that the area optimized 8-bit 2-input XOR and 3-input Majority gates require 4.47x and 4.16x less area, respectively, at the expense of 5% and 7% delay increase, respectively, without inducing any power consumption overhead. Finally, we discuss factors that are limiting the currently achievable parallelism to 8 for phase based gate output detection and demonstrate by means of OOMMF simulations that this can be increased 16 for threshold based detection based gates.

GEM‐2A: A programmable broadband helicopter‐towed electromagnetic sensor

We present a new helicopter‐towed broadband electromagnetic sensor, GEM‐2A, for mineral prospecting and geologic mapping. The sensor uses one set of transmitter and receiver coils for a multifrequency operation. For a given survey, the user initially specifies a set of operational frequencies in the current bandwidth of 90 Hz to 48 kHz. The transmitter coil then emanates a current waveform that contains all specified frequencies. The duration of this current waveform, called the base period, is typically 1/30 s (a submultiple of local powerline frequency) resulting in an overall data rate at 30 Hz. Receiver channels digitize the secondary field into a time series over a base period, which is then subjected to discrete sine and cosine transforms or convolutions at each transmitted frequency to produce the raw in‐phase and quadrature data. Additional convolutions may be included for passively monitoring environmental noise, including powerline emissions. The entire operation, including the system upload/download and realtime monitoring and communication, is done in Microsoft Windows. The fact that the sensor contains only a single set of coils for the broadband operation provides several unique advantages, some of which include (1) co‐relatable and coherent drift characteristics among frequencies, (2) spectral integrity among frequencies that may be useful for anomaly classification and, possibly, mineral discrimination, (3) tolerance to sferics, (4) tolerance to powerline noise, and (5) light tow body with minimal cockpit hardware suitable for a small helicopter. This paper presents the sensor construction, operation, and data examples.