In this paper, first, by introducing Holstein-Primakoff representation of α-deformed algebra, we achieve the associated non-linear coherent states, including su(2) and su(1, 1) coherent states. Second, by using waveguide lattices with specific coupling coefficients between neighbouring channels, we generate these non-linear coherent states. In the case of positive values of α, we indicate that the Hilbert size space is finite; therefore, we construct this coherent state with finite channels of waveguide lattices. Finally, we study the field distribution behaviours of these coherent states, by using Mandel Q parameter.

The amplitude and phase imbalances of the in-phase (I) and quadrature (Q) branches inherent in the direct conversion receiver structure cause the generation of image frequency interference signals. In this paper, a frequency-domain I/Q imbalance calibration algorithm is proposed for wideband direct conversion receivers. The I/Q imbalance model is rebuilt by applying the infinitesimal method and FFT algorithm. The mathematical expressions for the exact computation of the I/Q imbalance parameters are derived based on the frequency-domain statistical properties of the baseband signal. The two phase parameters, frequency-dependent I/Q imbalance (FD-IQI) and frequency-independent I/Q imbalance (FI-IQI), are separated according to the parity properties of the imbalance parameter. To avoid the interference from the transmitter, the receiver impairment estimation is performed using a frequency offset (FO) DC training signal, and a low-cost real-valued compensation (RVC) filter is introduced to correct the impairments of the received signal. The performances of the proposed calibration model are evaluated through simulations and experiments. The simulation results show that the image rejection ratio (IRR) is improved to 80-120 dBc and can also exceed 40 dBc at high noise levels. The experimental results based on the CX9261A evaluation board show that the average IRR of the multi-tone signal is increased by 24.99 dB, and the IRR of the wideband signal is increased by 19.08 dB.

Frequency-dependent I/Q imbalance and frequency-independent I/Q imbalance are the major impairments in wideband zero-IF receivers, and they both cannot be ignored. In this paper, a blind calibration model is designed for compensating these I/Q imbalances. In order to accurately estimate the imbalance parameters with low cost, a classification rule is proposed according to the frequency-domain statistical characteristics of the received signal. The calibration points in the frequency-domain are divided into two groups. Then, the amplitude imbalance and the frequency-dependent phase imbalance are derived from the group of signal points and, separately, the frequency-independent phase imbalance is calculated from the group of noise points. In the derivation of the frequency-dependent phase imbalance, a general fitting model suitable for all signal points is proposed, which does not require special calculations for either DC point or f_s/2 point. Then, a finite impulse response (FIR) real-valued filter is designed to correct the impairments of received signal. The performances of the proposed calibration model are evaluated through both simulations and experiments. The simulation results show the image rejection ratio (IRR) improvement to around 35–45 dBc at high signal-to-noise ratio (SNR). Based on the mismatched data of the ADRV9009 evaluation board, the experimental results exhibit the IRR improvement of both multi-tone and wideband signals to about 30 dBc.

This brief presents a low phase noise class-C voltage-controlled oscillator with bond wire inductors. To improve the Q-factor of inductors, the voltage-controlled oscillator employs bond wires as the inductors of the resonators. A transient-analysis-compatible equivalent circuit is proposed to precisely estimate the influence of mutual inductance, parasitic components and silicon substrate. Possible phenomena of oscillation mode ambiguity and oscillation failure are analyzed to be relative with the magnetic coupling between bond wires. An equation is derived to set up the relation among oscillation mode, bond wire coupling and frequency ratio of adjacent oscillators. And a costless placement reorder method is proposed to prevent the oscillator cores from oscillating failure and mode ambiguity. The voltage-controlled oscillator is implemented in a 65-nm CMOS process. Ten groups of gold double bond wires with a 20 μm diameter, 70 μm height and 800 μm horizontal length are adopted as the inductors. The total tuning range of the oscillator is from 2.22 GHz to 4.46 GHz. When oscillating at 4.46 GHz and the output frequency divide ratio is 2, the output signal provides phase noise performance of -137.3 dBc/Hz at 1 MHz offset from 2.23 GHz. The maximum power consumption is 38 mW and each oscillator core occupies a chip area of only 0.112 mm.

In this paper, we present a broadband Ka-band LNA using 0.15-µm GaAs pseudomorphic high electron mobility transistor (pHEMT) process. By using bandwidth enhancement techniques and deep negative feedback technology, the LNA achieves relatively broadband performances. The LNA attains 20 dB small signal gain from 25 to 40 GHz and shows a measured noise figure of 2.8 dB from 25 to 40 GHz with 230-mW dc power consumption. The input and output return loss of the LNA is less than 8 dB, which is competitive compared with other published Ka-band LNAs. The size of the chip is 2.5 mm × 1.2 mm.