Mitsuhiro Shimozawa

A monolithic even harmonic quadrature mixer using a balance type 90 degree phase shifter for direct conversion receivers

This paper proposes a novel circuit configuration of an even harmonic quadrature mixer (EHQMIX) for direct conversion receivers. In this EHQMIX, a 90 degree phase shifter consists of balance type high pass and low pass filters, and it does not require any circuits connecting to the ground plane. So this configuration is suitable for low cost monolithic IC without any via-holes, because amplitude and phase imbalance caused by inductance included in wires and leads of a package for circuits to the ground plane can be reduced. A developed L-band MMIC achieves good quadrature detecting characteristics.This paper proposes a novel circuit configuration of an even harmonic quadrature mixer (EHQMIX) for direct conversion receivers. In this EHQMIX, a 90 degree phase shifter consists of balance type high pass and low pass filters, and it does not require any circuits connecting to the ground plane. So this configuration is suitable for low cost monolithic IC implementation without any via-holes, because amplitude and phase imbalance, caused by the inductance included in the wires and leads of a package, can be reduced for circuits connected to the ground plane. A developed L-band MMIC achieves good quadrature detection characteristics.

A novel, sub-harmonic pumping direct conversion receiver with high instantaneous dynamic range

A novel sub-harmonic pumping direct conversion receiver (SHP-DCR) employing antiparallel diode pair (APDP) is proposed for high instantaneous dynamic range receivers used in mobile communications. The proposed SHP-DCR can suppress even harmonic mixing products, such as second order intermodulation (IM2) and LO noise that interfere a desired baseband signal. Moreover, the design condition of load resistance is indicated by analytical and experimental approaches for improving diode mixer disadvantages of lower conversion gain and higher LO power. A developed L-band SHP-DCR without a low noise amplifier achieves NF of 18.5 dB, IP3 at input port of 3 dBm and IM2 is below -90 dB in the actual input range.

A passive-type even harmonic quadrature mixer using simple filter configuration for direct conversion receiver

A passive-type even harmonic quadrature mixer using simple filter configuration for direct conversion receiver is presented. All circuits in the mixer are composed of passive elements. Diplexers of this mixer consist of simple high pass and low pass filters enough to realize a mixer with small size. This mixer is suitable for a mobile handset, because no DC consumption is required and it is easy to design and manufacture from its simple configuration. A developed mixer achieved good RF characteristics for direct conversion receivers.

A parallel connected Marchand balun using spiral shaped equal length coupled lines

This paper presents a 6-20 GHz broadband planar monolithic balun. To get a broadband characteristic without narrow spaced coupled transmission lines, a parallel connected Marchand balun with spiral shaped equal length coupled lines are used. A developed monolithic balun achieves the maximum insertion loss of 5 dB including 3 dB power splitting loss from 6 to 20 GHz.

2 GHz band even harmonic type direct conversion receiver with ABB-IC for W-CDMA mobile terminal

A 2 GHz band even harmonic type direct conversion receiver (EH-DCR) is proposed for the W-CDMA mobile terminal. Because of the well-matched anti-parallel diode pair used in the proposed EH-DCR, the receiver can reduce even order mixing products that degrade sensitivity characteristics. Also the proposed EH-DCR can achieve low current consumption with a passive mixer approach. In this paper, the overall receiver with an RF block, an analog baseband IC (ABB-IC) and a demodulator is demonstrated to indicate the effectiveness on the proposed RF architecture. The described evaluation results indicate high instantaneous dynamic range with high sensitivity.

An even harmonic mixer using self-biased anti-parallel diode pair

This paper presents a novel even harmonic mixer using self-biased anti-parallel diode pair (APDP). Resistors for self-bias are employed in APDP, and voltage differences in D.C. arise at each diode when LO power is applied. As increasing of LO power, voltage differences become larger, so maximum voltages of LO wave added to each diode are almost constant and conversion loss of the mixer is kept constantly. In the developed L-band even harmonic mixer using self-biased APDP for a direct conversion receiver, fluctuation of voltage conversion gain is below 1 dB with LO power of from 0 dBm to 14 dBm.

Integrated even harmonic type direct conversion receiver for W-CDMA mobile terminals

This paper is the first demonstration of the overall performance of the integrated even harmonic type direct conversion receiver (EH-DCR) with the RAKE receiver. The configuration of the integrated EH-DCR and its evaluation results based on the 3GPP definition are indicated. The RX LTCC module with the SiGe RX-IC, and BiCMOS ABB-IC are developed to achieve high integration of the receiver with filters. The integrated EH-DCR with low second order distortion can achieve high sensitivity and selectivity of the W-CDMA receiver, even with interference due to the transmitting signal. Described evaluation results satisfy the specifications defined by 3GPP. This paper clarifies effectiveness of the integrated EH-DCR for the third generation mobile terminals.

An even harmonic type direct conversion SiGe-MMIC receiver for W-CDMA mobile terminals

An even harmonic type direct conversion MMIC receiver for W-CDMA mobile terminals in SiGe HBT technology is described. A 2-stage low noise amplifier (LNA) and two self biased anti-parallel diode pairs (APDPs) for even harmonic mixer (EH-MIX) are integrated into a single chip. The LNA employed dual bias feed circuit to improve the output power and linearity. The EH-MIX can obtain high IIP2 by using APDP. Noise performance of Schottky barrier diode (SBD) for APDP fabricated in SiGe process is lower than that of conventional SBD in the market. Both fabricated LNA and EH-MIX demonstrated high RF performances, and they are applicable to RF front-end of W-CDMA mobile terminals.

0.8-5.2 GHz band SiGe-MMIC Q-MIX for a multi-band multi-mode direct conversion receiver

By employing a 14 GHz static frequency divider and broadband SiGe-HBT unit mixers, a 0.8-5.2 GHz band Q-MIX is developed using a 0.35 /spl mu/m SiGe BiCMOS process. The fabricated Q-MIX has constant conversion gain (Gc) over the wide baseband (BB) frequency range up to 100 MHz and performs good I/Q balance (<0.17 dB, <3.6 degrees) over the wide RF frequency range of 0.8-5.2 GHz.

A flexible and precise APAA system with RF modules including a signal generator

We propose a new concept of an active phased array antenna (APAA) system that realizes multi-frequency and multi-modulation beam forming simultaneously in an array. The proposed APAA system consists of RF modules including an RF signal generator. A distributed array radar system with the proposed configuration can be simplified by not transmitting a signal in RF at the interconnect equipments of modules. The proposed APAA has architectures to measure and compensate the characteristic variations between RF modules by itself. Key features of the proposed APAA are verified by measurements. Transmitter block of the RF module with three SiGe-ICs and signal distribution system are fabricated. The RF module generates various modulated signals of 1Gs/s and operates in C-Ku bands, and measures the RF characteristic variations. The signal distribution system compensates the phase fluctuation of the distributed signals.