Dynamic range enhancements in radio receivers by means of frequency retranslation

Nesimoglu, T.
Charalampopoulos, Z.
Warr, P. A.
Beach, M. A.
In this study, a receiver architecture is presented that may be used for linearisation or for large signal interference suppression. In linearisation mode, an error signal that consists of intermodulation distortion products is obtained and used for predistorting the receiver. Experimental results demonstrate > 16 dB improvement of third-order input intercept point when used in a superheterodyne topology. When used in a direct conversion receiver topology, 7-dB improvement of second-order input intercept point is obtained. In interference suppression mode, an error signal that consists of high-level interferers spectrally close to a small wanted signal is obtained and used for predistorting the receiver. Experimental results demonstrate 14-dB enhancement of spurious-free dynamic range of the receiver.


Triple stub circuit topology as simultaneous insertion phase, amplitude and impedance control circuit for phased array applications
Unlu, M.; Demir, Şimşek; Akın, Tayfun (Institution of Engineering and Technology (IET), 2012-10-23)
This study shows that the well-known triple stub circuit topology can also be used for controlling the insertion phase and amplitude of a given signal simultaneously, as well as preserving its impedance transformation ability. The triple stub circuit topology, which is nothing but an extension of the conventional double stub loaded-line phase shifter, results in one more degree of freedom to its solution when it is solved for its insertion phase. This additional degree of freedom not only brings the impedan...
Metasurface Lens for Ultra-Wideband Planar Antenna
Yesilyurt, Omer; Sayan, Gönül (Institute of Electrical and Electronics Engineers (IEEE), 2020-02-01)
In this article, an ultra-wideband metasurface lens is designed and integrated into an antipodal Vivaldi antenna (AVA) to improve its radiation directivity without affecting its efficiency and return loss characteristics. The metasurface lens consists of high permittivity metamaterial unit cells which resonate at frequencies far away from the operation bandwidth of 1-6 GHz. Electric field distributions of the antennas show that the near-field behaves more planar for the metasurface lens loaded AVA, as compa...
Joint spatial and temporal channel-shortening techniques for frequency selective fading MIMO channels
Toker, Canan; Chambers, JA; Baykal, Buyurman (2005-02-01)
It is well understood that the maximum likelihood estimator is a powerful equalisation technique for frequency selective fading channels, and in particular for MIMO systems. The complexity of this estimator, however, grows exponentially with the number of users and multipath taps, hence limiting the use of this algorithm in MIMO systems. In the paper, the authors propose a joint spatial and temporal channel-shortening filter as a pre-processor to reduce significantly the complexity of a maximum likelihood e...
Radar target classification method with reduced aspect dependency and improved noise performance using multiple signal classification algorithm
SEÇMEN, MUSTAFA; Sayan, Gönül (Institution of Engineering and Technology (IET), 2009-12-01)
This study introduces a novel aspect and polarisation invariant radar target classification method based on the use of multiple signal classification (MUSIC) algorithm for feature extraction. In the suggested method, for each candidate target at each designated reference aspect, feature matrices called 'MUSIC spectrum matrices (MSMs)' are constructed using the target's scattered data at different late-time intervals. An individual MSM corresponds to a map of a target's natural resonance-related power distri...
Performance Enhancement of the Single-Phase Series Active Filter by Employing the Load Voltage Waveform Reconstruction and Line Current Sampling Delay Reduction Methods
Senturk, Osman S.; Hava, Ahmet Masum (Institute of Electrical and Electronics Engineers (IEEE), 2011-08-01)
This paper proposes the waveform reconstruction method (WRM), which is utilized in the single-phase series active filter's (SAF's) control algorithm, in order to extract the load harmonic voltage component of voltage harmonic type single-phase diode rectifier loads. Employing WRM and the line current sampling delay reduction method, a single-phase SAF compensated system provides higher harmonic isolation performance and higher stability margins compared to the system using conventional synchronous-reference...
Citation Formats
T. Nesimoglu, Z. Charalampopoulos, P. A. Warr, and M. A. Beach, “Dynamic range enhancements in radio receivers by means of frequency retranslation,” IET MICROWAVES ANTENNAS & PROPAGATION, pp. 489–496, 2012, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/67664.