Optically reconfigurable CPW filters for UWB applications

A miniature optically reconfigurable ultra-wideband CPW bandpass filter is proposed. With the optical switch in the ON state (200W), the circuit behaves as a bandpass filter while in the OFF state (0W), the circuit behaves as a bandstop filter within the same frequency band. The simulation results of the proposed bandpass/bandstop filter are presented.

Nonlinear distortion evaluation of reconfigurable RF circuits in wireless communication systems

A compact highly linear microstrip dual - mode optically switchable filter and a reconfigurable power amplifier are presented. The key characteristics of the dual - mode switchable filter are investigated and described. A second order filter design procedure is outlined to facilitate the realisation of Butterworth and Chebyshev functions. The proposed filter was built and tested with an optical switch, which comprised of a silicon dice acti vated using near infrared light. The measured and simulated results are in good agreement. The measured insertion loss in the ON state was 3.0 dB the isolation in the OFF state was 45 dB at the centre frequency. An evaluation of filter distortion is presen ted for digitally modulated M - QAM and M - QAM OFDM singals.

Optically reconfigurable E-plane waveguide resonators and filters

This paper presents an optically reconfigurable E-plane waveguide resonator and filter. N-type silicon dice doped with phosphorus is used as the switching element and is connected to the edge of a metallic fin. Illumination of the silicon dice allows realization of a different length of the fin, thus creating a shift in resonant frequency of the structure. Frequency tuning range up to about 5.2% is achieved for the resonator as well as the filter. Measurements on a fabricated optically reconfigurable resonator confirm the accuracy of the design procedure. Measured responses show good agreement with simulation.

Miniaturised sharp rejection bandpass filter with reconfigurable bandwidth for UWB applications

A novel, compact and highly selective microstrip bandpass filter with bandwidth reconfigurability for ultra-wideband (UWB) applications is presented. The proposed design uses stepped impedance resonator (SIR) for realization of bandpass filter (BPF) and employs a single varactor diode (BB135-NXP) for the purpose of reconfiguring bandwidth. Additionally, to improve the selectivity between passband edges, a cross-coupling between I/O feed lines is introduced which generated pairs of attenuation poles at each side of the passband. Measurements on a fabricated reconfigurable filter confirm the accuracy of the design procedure. Measured responses show good agreement with simulation. The proposed filter is able to achieve significant size reduction (8.5 mm × 7.1 mm excluding the feeding ports) as compared to the conventional bandpass filters with reconfigurable bandwidth.

Colour Sensation and Empathy: Arthur Schopenhauer's Negative Philosophy and Colour Theory as the Basis of an Elemental Colour Architecture

Arthur Schopenhauer proposed a theory of colour as a consequence of his first hand knowledge of J.W. Goethe’s experiments with color phenomena. This colour theory can be used to explore an interesting proposition Schopenhauer made about architecture. For Schopenhauer, architecture is about feelings, not about functions or forms, its purpose as an art is to reveal the principles of primitive forces, specifically gravity and rigidity. For Schopenhauer, architecture expresses these forces in the poised equilibrium of massive structures built out of stone. Schopenhauer was inclined to believed that architecture had already achieved its most perfect expression in Greek temple architecture. However; he did offer one possibility for architectural research: this was the suggestion that architecture was also concerned with the expression of light. It seems never to have occurred to Schopenhauer to use his colour theory to speculate about light in architecture. This paper explores some of the implications of Schopenhauer’s theory of colour for his aesthetics of architecture?

Median Filter Architecture by Accumulative Parallel Counters

The time to process each of the W/B processing blocks of a median calculation method on a set of N W-bit integers is improved here by a factor of three compared with literature. The parallelism uncovered in blocks containing B-bit slices is exploited by independent accumulative parallel counters so that the median is calculated faster than any known previous method for any N, W values. The improvements to the method are discussed in the context of calculating the median for a moving set of N integers, for which a pipelined architecture is developed. An extra benefit of a smaller area for the architecture is also reported.