Orthogonality Condition of Spatial Multiplexing

•Spatial Multiplexing is the main function of MIMO system. The spatial multiplexing gain that relates to throughput enhancement depends on orthogonality condition of MIMO antennas.
•In LOS or non-scattering MIMO environment or outdoor area, orthogonality condition is St x Sr/R>= l/M, where St and Sr are transmit and receive antenna spacings respectively, R is the range from transmit antennas to receive antennas, M is the number of receive antennas, the transmit antenna number N is not used in this condition.
•In NLOS or scattering MIMO environment or indoor area, orthogonality condition is [2 x Dt/(N-1)] x [2 x Dr/(M-1)]>=R x l/M, where Dt and Dr are transmit and receive scattering radii respectively, R is the range from transmit scattering center to receive scattering center, N and M are the numbers of transmit and receive antennas respectively.
–The scattering is made by scatterers in MIMO environment, which can be modeled by omni-directional ideal reflectors.
–The scatterers are assumed to be located sufficiently far from antennas for holding plane-wave assumption and further assumed such that Dt (or Dr) is much less than R for meeting local scattering condition.

Correlation Coefficient of Antenna Diversity

•Correlation Coefficient r = exp [-0.0021 x S x f x sqrt (0.4 x R)] by CCIR (now ITU-R), where
–S: antenna vertical spacing in m
–f: frequency in GHz
–R: range in Km

Antennas and Incoming Multipath Waves

•If the incoming multipath wave distribution in space is not wide-dispersive, then Correlation Coefficient r could not get benefit from the differentiation in antenna positions (or the separation in space)
•If the incoming multipath wave distribution in angle is not isotropic, then Correlation Coefficient r could not get benefit from the differentiation in antenna patterns (or the separation in angle)

Diversity and Multiplexing of MIMO

•In general, the greater the space separation the less the correlation coefficient and so the better the Multiplexing or Diversity, if it will not generate side-effect like differential propagation loss
–Antenna space separations of multiplexing and diversity antenna structures have the order of multiple wavelengths
•The greater the angle separation the less the correlation coefficient and so the better the multiplexing or diversity as well, if it will not generate side-effect like blocking
–Antenna angle separations of multiplexing and diversity antenna structures have the order of multiple beamwidths, or
–Antenna pattern differentiations of multiplexing and diversity antenna structures have orthogonality or well compensation between each other, e.i. null-patterns relative to peak-patterns (and furthermore, cross-polarizations relative to co-polarizations)

Diversity and Multiplexing Gains

•Diversity Gain = (Ideal Diversity Gain) x SQRT(1 – r), where the Ideal Diversity Gain is proportional to the dimensions n, m or n x m (m for Transmit diversity gain, n for receive diversity gain, n x m for total system diversity gain), Correlation Coefficient r is a function of
1.Separable Antenna Patterns (angular separation)
2.Separable Antenna Positions (spatial separation)
3.Isotropic distribution of incoming multipath waves (angular spread)
4.Wide-dispersive distribution of incoming multipath waves (delay spread)
•Multiplexing Gain is related to Correlation Coefficient r as well, except that the Ideal Multiplexing Gain is rather proportional to the dimension either m or n, whichever is less in the system

Beamforming of Smart Antenna

* The span of antenna spacings (or squint-angles) should be adjusted and traded off to get the balance between accuracy and ambiguity of direction finding by phase-comparison (or amplitude-comparison)
–Antenna spacings of phased-array beamforming antenna structure have the order of fraction wavelengths, otherwise they will generate side-effect like ambiguity due to grating lobes. Note that spacing is defined as the space separation of antenna elements
–Antenna squint-angles of amplitude-array beamforming antenna structure similarly have the order of fraction beamwidths, otherwise it will generate side-effect like ambiguity due to side lobes. Note that squint-angle is defined as half of the angle separation of antenna elements.

Beamforming Gain

•Beamforming Gain, i.e. Phase-comparison (or Amplitude-comparison) Array Gain is proportional to the Ideal Beamforming Gain which is related to the dimensions n, m or n x m (m for transmit beamforming gain, n for receive beamforming gain, n x m for total system beamforming gain), and conditionally related to the Correlation Coefficient r
-In some cases of LOS and so forth, the space distribution of incoming multipath waves is limited and fixed in path rather than wide-dispersive or of opportunity in time, so the individual antennas had better have in-phase waveforms to raise the combined gain
-In the same cases, the angle distribution of incoming multipath waves is limited and fixed in direction rather than isotropic or of opportunity in angle, so the individual antennas had better have identical patterns to raise the combined gain

Normalized total field of Phased-Array with Butler-Matrix

•Normalized total field of phased array with beams formed by Butler Matrix, i.e.
–Em(r) = {sin(N/2)[(2pd/l)sinr- (2m+1)](p/N)]} / Nsin(1/2)[(2pd/l)sinr- (2m+1)](p/N)], if elevation n = 0, where r = azimuth and m = the serial no. of the beam

Normalized total field of Phased-Array

•Define Array factor f(y) = Normalized total field En(y) = E(y)/Emax, where Emax= N, if y=0, e.i.
–f(y) = (1/N)sin(Ny/2) / sin(y/2);
•Define Array factor f(f,q) = Normalized total field En(f,q) = E(f,q)/Emax, where Emax= N if q= f= p/2, e.i.
–f(f,q) = {sin[(pd/l)Ncosfsinq] / Nsin[(pd/l)cosfsinq], or
–f(f) = {sin[(pd/l)Ncosf] / Nsin[(pd/l)cosf], if q= p/2;
•Define Array factor f(n,r) = Normalized total field En(n,r) = E(n,r)/Emax, where Emax= N if elevation n= (p/2)- q= (p/2)- p/2= 0 and azimuth r= (p/2)- f= (p/2)- p/2= 0, e.i.
–f(n,r) = {sin[(pd/l)Ncosnsinr] / Nsin[(pd/l)cosnsinr], or
–f(r) = {sin[(pd/l)Nsinr] / Nsin[(pd/l)sinr], if n= 0.
•Normalized total field or array factor determine DOA, Direction of Arrival, in general,
–r at any n (or f at any q), or specifically
–r at n= 0 (or f at q= p/2)

Total field of Phased-Array

•Total field = E(y), where phase difference y=(2pd/l)cosfsinq, e.i.
–E(y) = 1+ exp(jy)+ exp(j2y)+ exp(j3y)+ exp(j4y)+ exp(j5y)+ …+ exp[j(N-1)y]
–= [1- exp(jNy)]/ [1- exp(jy)]
–= [exp(jNy/2)/ exp(jy/2)]/ {[exp(jNy/2)- exp(-jNy/2)]/ [exp(jy/2)- exp(-jy/2)]
–= exp[j(N-1)y/2][sin(Ny/2)/ sin(y/2)], refer to the first element, or
–= sin(Ny/2)/ sin(y/2), refer to the center element

Cellular Coexistence with WiFi

•WiFi Side
–Add-on filter to block the spurs of cellular bands (GSM/3GPP) to have WiFi RX immune from interference
–Add-on filter to reject WiFi out-of-band spurs coming from WiFi TX in compliance with the requirement of regulation
•Cellular Side
–Add-on filter to block the spurs of WiFi bands to have cellular RX immune from interference
–Add-on filter to reject cellular out-of-band spurs coming from cellular TX in compliance with the requirement of regulation

IO Interface trend

•From Parallel Bus Move to Serial Bus
•Use Serial IO Interface of
–PCI express (for High-Throughput WiFi)
–USB (for WiFi and WiMAX)
–SDIO (for Low-Throughput WiFi)

Bluetooth Coexistence Schemes of WiFi

•1-wire handshake
–input: BT_ACTIVE
•2-wire handshakes
–input: BT_PRIORITY
–output: WL_ACTIVE
•3-wire handshakes
–input: BT_REQUEST, BT_STATE
–output: BT_GRANTn
•4-wire handshakes
–input: BT_REQUEST, BT_STATE, BT_FREQ
–output: BT_GRANTn

Manufacturing Test Support Equipment

•Mobile-WiMAX 16e Testing
–LitePoint: IQmax/ IQsignal
–Agilent: MXA/ MXG
•WiFi 11n Testing
–LitePoint: IQflex/ IQfact
–Agilent: WTM with Adapter

Capabilities of Production Supports

•MVT test supports of HVM production with regards to plan, equipment, tool and fixture
•Supports to incoming, in-process and outgoing quality-tests
•Supports to corrective analyses and actions
•Supports to solve the issues of DPM
•Packaging, assembling and integration technical supports

Dipole and Patch Arrays

•Vertically Linear Dipole Array
–High-gain Omni-directional Antenna
•Vertically Linear Dipole Array with back-plane
–Sectored Antenna
•Vertically Linear Patch Array
–High-gain Sectored Antenna
•Two-dimension Dipole Array with back-plane
–Directional Antenna
•Two-dimension Patch Array
–High-gain Directional Antenna

11n Multi-Radio Reality

•2T2R AP (Personal Router) + 1T1R STA (Handheld)
–Uplink: SIMO/ Downlink: MISO
•2T2R AP + 1T2R STA (LE PC Card or Handheld)
–Uplink: SIMO/ Downlink: MIMO
•2T2R AP + 2T2R STA (ME PC Card)
–Uplink: MIMO/ Downlink: MIMO
•2T2R AP + 2T3R STA (HE PC Card)
–Uplink: MIMO/ Downlink: MIMO
•2T3R AP (Home Gateway) + 1T1R STA
–Uplink: SIMO/ Downlink: MISO
•2T3R AP + 1T2R STA
–Uplink: SIMO/ Downlink: MIMO
•2T3R AP + 2T2R STA
–Uplink: MIMO/ Downlink: MIMO
•2T3R AP + 2T3R STA
–Uplink: MIMO/ Downlink: MIMO
•3T3R AP (Enterprise AP) + 1T1R STA
–Uplink: SIMO/ Downlink: MISO
•3T3R AP + 1T2R STA
–Uplink: SIMO/ Downlink: MIMO
•3T3R AP + 2T2R STA
–Uplink: MIMO/ Downlink: MIMO
•3T3R AP + 2T3R STA
–Uplink: MIMO/ Downlink: MIMO

The elements of Minder-line Monopole Antenna

•Radiator
•Feed
•Short
•Reflector
•Parasitic Object
•Dielectric Material
•Radome

Minder-line Monopole Antenna

•Single-band versus multi-band
•Single-feed versus multi-feed
•Organic dielectric versus LTCC dielectric
•Printed versus Chip-surface-mounted

SiP Layout Tools

•RF:
–Cadence Virtuoso (SiP RF Architect, SiP RF Layout) and 3rd party SiP RF SI
•Digital:
–Cadence Encounter (SiP Digital Architect, SiP Digital Layout and SiP Digital SI)
•Hybrid:
–Cadence Precision Router